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A Uniform Resource Name (URN) Namespace for Sources of Law (LEX)
draft-spinosa-urn-lex-21

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This is an older version of an Internet-Draft whose latest revision state is "Active".
Authors PierLuigi Spinosa , Enrico Francesconi , Caterina Lupo
Last updated 2024-03-18 (Latest revision 2023-12-15)
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draft-spinosa-urn-lex-21
Network Working Group                                         P. Spinosa
Internet-Draft                                                          
Intended status: Informational                            E. Francesconi
Expires: 17 June 2024           Consiglio Nazionale delle Ricerche (CNR)
                                                                 C. Lupo
                                                        15 December 2023

    A Uniform Resource Name (URN) Namespace for Sources of Law (LEX)
                        draft-spinosa-urn-lex-21

Abstract

   This document describes a Uniform Resource Name (URN) Namespace
   Identification (NID) convention for identifying, naming, assigning,
   and managing persistent resources in the legal domain.  This
   specification is published to allow adoption of a common convention
   by multiple jurisdictions to facilitate ease of reference and access
   to resources in the legal domain.
   This specification is an independent submission to the RFC series.
   It is not a standard, and does not have the consensus of the IETF.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on 17 June 2024.

Copyright Notice

   Copyright (c) 2023 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.1.  The Purpose of Namespace "lex"  . . . . . . . . . . . . .   4
     1.2.  Community Considerations  . . . . . . . . . . . . . . . .   4
     1.3.  Background  . . . . . . . . . . . . . . . . . . . . . . .   5
     1.4.  General Characteristics of the System . . . . . . . . . .   7
     1.5.  Linking a LEX Name to a Document  . . . . . . . . . . . .   9
     1.6.  Use of LEX Names in References  . . . . . . . . . . . . .   9
     1.7.  Definitions . . . . . . . . . . . . . . . . . . . . . . .  10
     1.8.  Terminology . . . . . . . . . . . . . . . . . . . . . . .  10
     1.9.  Syntax Used in this Document  . . . . . . . . . . . . . .  10
     1.10. Namespace Registration  . . . . . . . . . . . . . . . . .  10
   2.  Registration of LEX . . . . . . . . . . . . . . . . . . . . .  10
     2.1.  Identifier Structure  . . . . . . . . . . . . . . . . . .  10
     2.2.  Jurisdiction-code Register  . . . . . . . . . . . . . . .  12
     2.3.  Conformance with URN Syntax . . . . . . . . . . . . . . .  14
     2.4.  Validation Mechanism  . . . . . . . . . . . . . . . . . .  14
     2.5.  Scope . . . . . . . . . . . . . . . . . . . . . . . . . .  14
   3.  General Syntax and Features of the LEX Identifier . . . . . .  14
     3.1.  Allowed and Not Allowed Characters  . . . . . . . . . . .  14
     3.2.  Reserved Characters . . . . . . . . . . . . . . . . . . .  15
     3.3.  Case Sensitivity  . . . . . . . . . . . . . . . . . . . .  15
     3.4.  Unicode Characters outside the ASCII Range  . . . . . . .  15
     3.5.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .  17
     3.6.  Date Format . . . . . . . . . . . . . . . . . . . . . . .  18
   4.  Specific Syntax and Features of the LEX Identifier  . . . . .  18
     4.1.  Spaces, Connectives and Punctuation Marks . . . . . . . .  19
     4.2.  Acronyms  . . . . . . . . . . . . . . . . . . . . . . . .  19
     4.3.  Ordinal Numbers . . . . . . . . . . . . . . . . . . . . .  19
   5.  Creation of the Source of Law LEX Identifier - Baseline
           structure . . . . . . . . . . . . . . . . . . . . . . . .  19
     5.1.  Basic Principles  . . . . . . . . . . . . . . . . . . . .  19
     5.2.  Model of Sources of Law Representation  . . . . . . . . .  20
     5.3.  The Structure of the Local Name . . . . . . . . . . . . .  21
     5.4.  Structure of the Document Identifier at "Work" Level  . .  22
     5.5.  Aliases . . . . . . . . . . . . . . . . . . . . . . . . .  23
     5.6.  Structure of the Document Identifier at "Expression"
           Level . . . . . . . . . . . . . . . . . . . . . . . . . .  23
     5.7.  Structure of the Document Identifier at "Manifestation"
           Level . . . . . . . . . . . . . . . . . . . . . . . . . .  25
     5.8.  Sources of Law References . . . . . . . . . . . . . . . .  26

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   6.  Specific Syntax of the Identifier at "Work" Level . . . . . .  28
     6.1.  The authority Element . . . . . . . . . . . . . . . . . .  28
       6.1.1.  Indication of the Authority . . . . . . . . . . . . .  28
       6.1.2.  Multiple Issuers  . . . . . . . . . . . . . . . . . .  29
       6.1.3.  Indication of the Issuer  . . . . . . . . . . . . . .  29
       6.1.4.  Indication of the Body  . . . . . . . . . . . . . . .  29
       6.1.5.  Indication of the Function  . . . . . . . . . . . . .  29
       6.1.6.  Conventions for the Authority . . . . . . . . . . . .  30
     6.2.  The measure Element . . . . . . . . . . . . . . . . . . .  30
       6.2.1.  Criteria for the Indication of the Type of Measure  .  30
       6.2.2.  Further Specification to the Type of Measure  . . . .  30
       6.2.3.  Aliases for Sources of Law with Different Normative
               References  . . . . . . . . . . . . . . . . . . . . .  31
       6.2.4.  Relations between Measure and Authority in the
               Aliases . . . . . . . . . . . . . . . . . . . . . . .  31
     6.3.  The Details Element . . . . . . . . . . . . . . . . . . .  31
       6.3.1.  Indication of the Details . . . . . . . . . . . . . .  32
       6.3.2.  Multiple Dates  . . . . . . . . . . . . . . . . . . .  32
       6.3.3.  Unnumbered Measures . . . . . . . . . . . . . . . . .  33
       6.3.4.  Multiple Numbers  . . . . . . . . . . . . . . . . . .  33
     6.4.  The annex Element . . . . . . . . . . . . . . . . . . . .  34
       6.4.1.  Formal Annexes  . . . . . . . . . . . . . . . . . . .  34
       6.4.2.  Annexes of Annexes  . . . . . . . . . . . . . . . . .  34
   7.  Specific Syntax of the Version Element of the "Expression"  .  35
     7.1.  The version Element . . . . . . . . . . . . . . . . . . .  35
       7.1.1.  Different Versions of a Legislative Document  . . . .  35
       7.1.2.  Identification of the Version . . . . . . . . . . . .  36
   8.  Summary of the Syntax of the Uniform Names of the "lex"
           Namespace . . . . . . . . . . . . . . . . . . . . . . . .  37
   9.  The Procedure of Uniform Names Assignment . . . . . . . . . .  41
     9.1.  Specifying the jurisdiction Element of the LEX
           Identifier  . . . . . . . . . . . . . . . . . . . . . . .  41
     9.2.  Jurisdictional Registrar for Names Assignment . . . . . .  41
     9.3.  Identifier Uniqueness . . . . . . . . . . . . . . . . . .  42
     9.4.  Identifier Persistence Considerations . . . . . . . . . .  43
   10. Recommendations for the Resolution Process  . . . . . . . . .  43
     10.1.  The General Architecture of the System . . . . . . . . .  44
     10.2.  Catalogues for Resolution  . . . . . . . . . . . . . . .  45
     10.3.  Suggested Resolver Behaviour . . . . . . . . . . . . . .  45
   11. Security Considerations . . . . . . . . . . . . . . . . . . .  46
   12. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  46
   13. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  47
   14. References  . . . . . . . . . . . . . . . . . . . . . . . . .  47
     14.1.  Normative References . . . . . . . . . . . . . . . . . .  47
     14.2.  Informative References . . . . . . . . . . . . . . . . .  49
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  50

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1.  Introduction

1.1.  The Purpose of Namespace "lex"

   The purpose of the "lex" namespace is to assign a unique identifier,
   in well-defined format, to documents that are sources of law.  To the
   extent of this namespace, "sources of law" include any legal document
   within the domain of legislation, case law and administrative acts or
   regulations; moreover potential "sources of law" (acts under the
   process of law formation, as bills) are included as well.  Therefore
   "legal doctrine" is explicitly not covered.

   The identifier is conceived so that its construction depends only on
   the characteristics (details) of the document itself and, therefore,
   it is independent from the document on-line availability, its
   physical location, and access mode.  The identifier itself is
   assigned by the jurisdiction of the identified document.  Even a
   document that is not available online may, nevertheless, have a LEX
   URN identifier.

   Such an identifier can be used as a way to represent references (and
   more generally, any type of relation) among various sources of law.
   In an on-line environment with resources distributed among different
   Web publishers, identifiers, in terms of uniform resource names,
   allow a simplified global interconnection of legal documents by means
   of automated hypertext linking.  LEX URNs consist of persistent and
   location-independent identifiers and are particularly useful when
   they can be mapped into or associated with locators such as HTTP
   URLs.  Moreover, LEX URNs details can be used as a reference to
   create HTTP-based persistent and location-independent identifiers
   [RFC3986].  Such kind of identifiers have been suggested within the
   set of principles and technologies, known as "Linked Data", as a
   basic infrastructure of the semantic web to enable data sharing and
   reuse on a massive scale.

1.2.  Community Considerations

   The use of the "lex" namespace facilitates the interoperability of
   information systems used in the Public Administration at the national
   and international level.  Moreover it allows the distribution of the
   legal information towards a federated architecture.  In such an
   architecture, documents are directly managed by the issuing
   authorities, with resulting benefits in information authenticity,
   quality and currency.  A shared identification mechanism of resources
   guarantees that a distributed system will be as efficient and
   effective as a comparable centralized system.

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   Creators of Internet content that references legal materials -
   including publishers operating well outside the traditional arenas of
   legal publishing - benefit by the registration of the namespace
   because it facilitates the linking of legal documents, whether by
   manual or automated means, and reduces the cost of maintaining
   documents that contain such references.

   Any citizen or organisation with Internet web browser capability will
   have the possibility to use the namespace and its associated
   application, registers, and resolution services, to facilitate
   document access (if available).

   LEX URNs also identify offline resources, for instance by making it
   easier for organizations such as legislative bodies, law libraries,
   and legal publishers to identify resources and generate links between
   such resources (e.g., for the purpose of stable citation).

1.3.  Background

   This specification of a unique identifier for legal documents follows
   a number of initiatives in the field of legal document management.

   Since 2001 the Italian Government, through the National Center for
   Information Technology in the Public Administration, the Ministry of
   Justice and CNR (the National Research Council of Italy) promoted the
   NormeInRete project.  It was aimed at introducing standards for
   sources of law description and identification using XML and URN
   techniques.

   Other national initiatives in Europe introduced standards for the
   description of legal sources [FRAN].  Collaborations between
   government, national research institutes, and universities, have
   defined national XML standards for legal document management, as well
   as schemes for legal document identification.  Outside of Europe,
   similar initiatives have addressed similar problems [FRAN].  Several
   of these identifiers are based on a URN schema.

   In today's information society the processes of political, social and
   economic integration of European Union member states as well as the
   increasing integration of the world-wide legal and economic processes
   are causing a growing interest in exchanging legal information
   knowledge at national and trans-national levels.  The growing desire
   for improved quality and accessibility of legal information amplifies
   the need for interoperability among legal information systems across
   national boundaries.  A common well-defined schema used to identify
   sources of law at international level is an essential prerequisite
   for interoperability.

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   Interest groups within several countries have already expressed their
   intention to adopt a shared solution based on a URN technique.
   The need for a unique identifier of sources of law in different EU
   Member States, based on open standards and able to provide advanced
   modalities of document hyper-linking, has been expressed in several
   conferences (as [LVI]) by representatives of the Publications Office
   of the European Union (OP), with the aim of promoting
   interoperability among national and European institution information
   systems.  Similar concerns have been raised by international groups
   concerned with free access to legal information, and the Permanent
   Bureau of the Hague Conference on Private International Law [HCPIL]
   that encourage State Parties to "adopt neutral methods of citation of
   their legal materials, including methods that are medium-neutral,
   provider-neutral and internationally consistent.".  In a similar
   direction the CEN Metalex initiative is moving, at European level,
   towards the definition of a standard interchange format for sources
   of law, including recommendations for defining naming conventions to
   them.

   The need of unique identifiers for sources of law is of particular
   interest also in the domain of case law.  This is acutely felt within
   both common law systems, where cases are the main law sources, and
   civil law systems, in order to provide an integrated access to cases
   and legislation, as well as to track the relationships between them.
   This domain is characterized by a high degree of fragmentation in
   case law information systems, which usually lack interoperability.

   In the European Union, the community institutions have stressed the
   need for citizens, businesses, lawyers, prosecutors and judges to
   become more aware not only of (directly applicable) EU law, but also
   of the various national legal systems.  The growing importance of
   national judiciaries for the application of Community law was
   stressed in the resolution of the European Parliament of 9 July 2008
   on the role of the national judge in the European judicial system.
   Similarly the the Council of the European Union has underlined the
   importance of cross-border access to national case law, as well as
   the need for its standardisation, in view of an integrated access in
   a decentralized architecture.  In this view the Working Party on
   Legal Data Processing (e-Law) of the Council of the European Union
   formed a task group to study the possibilities for improving cross-
   border access to national case law.  Taking notice of the report of
   the Working Party's task group the Council of the EU decided in 2009
   to elaborate on a uniform, European system for the identification of
   case law (ECLI: European Case-Law Identifier) and uniform Dublin
   Core-based set of metadata.

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   The Council of the European Union invited the Member States to
   introduce in the legal information systems the European Legislation
   Identifier (ELI), an http-based Semantic Web oriented identification
   system for European Union and Member States legislation.

   The LEX identifier (also referred in this text as "LEX name") is
   conceived to be general enough so as to provide guidance at the core
   of the standard and sufficient flexibility to cover a wide variety of
   needs for identifying all the legal documents of different nature,
   namely legislative, case-law and administrative acts.  Moreover, it
   can be effectively used within a federative environment where
   different publishers (public and private) can provide their own items
   of a legal document (that is there is more than one manifestation of
   the same legal document).

   Specifications and syntax rules of LEX identifier can be used also
   for http-based naming convention to cope with different requirements
   in legal information management, for example the need of having an
   identifier compliant with the Linked Open Data principles.

   This document supplements the required name syntax with a naming
   convention that interprets all these recommendations into an original
   solution for sources of law identification.

   The following entities support the publication of this proposal:

   *  CNR (National Research Council of Italy) - Italy;

   *  Agency for Digital Italy (AgID) - Presidency of the Council of
      Ministers - Italy;

   *  PRODASEN - IT Department of the Federal Senate - Brazil;

   *  LII (Legal Information Institute), Cornell Law School - USA.

1.4.  General Characteristics of the System

   The specifications in this document promote interoperability among
   legal information systems by defining a namespace convention and
   structure that will create and manage identifiers for legal
   documents.  The identifiers are intended to be:

   *  globally unique

   *  transparent

   *  reversible

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   *  persistent

   *  location-independent, and

   *  language-neutral.

   These qualities facilitate legal document management and a mechanism
   of stable cross-collections and cross-country references.

   Transparency means that given an act and its relevant metadata
   (issuing authority, type of measure, etc.), it is possible to create
   the related URN that is able to uniquely identify the related act in
   a manner that is reversible (from an act to its URN and from a URN to
   the related act).

   Language-neutrality is an especially important feature that promotes
   adoption of the standard by organizations that must adhere to
   official-language requirements.  This specification provides guidance
   to both public and private groups that create, promulgate, and
   publish legal documents.  Registrants wish to minimize the potential
   for creating conflicting proprietary schemes, while preserving
   sufficient flexibility to allow for diverse document types and to
   respect the need for local control of collections by an equally
   diverse assortment of administrative entities.

   The challenge is to provide the right amount guidance at the core of
   the specification while providing sufficient flexibility to cover a
   wide variety of needs.  LEX does this by splitting the identifier
   into parts.  The first part uses a pre- existing standard
   specification ("country/jurisdiction name standard") to indicate the
   country (or more generally the jurisdiction) of origin for the legal
   document being identified; the remainder ("local name") is intended
   for local use in identifying documents issued in that country or
   jurisdiction.

   The second part depends only on the system of sources of law
   identification operating in that nation and it is mainly composed by
   formalized information related to the enacting authority, the type of
   measure, the details and possibly the annex.

   The identification system based on uniform names includes:

   *  a schema for assigning names capable of representing unambiguously
      any addressed source of law (namely legislation, case law and
      administrative acts), issued by any authority (intergovernmental,
      supranational, national, regional and local) at any time (past,
      present and future);

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   *  a resolution mechanism - in a distributed environment - that ties
      a uniform name to the on-line location of the corresponding
      resource(s).

   This document considers the first of these requirements.  It also
   contains a few references to the architecture of the resolution
   service and to the corresponding software.

1.5.  Linking a LEX Name to a Document

   The LEX name is linked to the document through meta-information which
   may be specified as follows:

   *  within the document itself through a specific element within an
      XML schema or by an [W3C.HTML] META tag;

   *  externally by means of a Resource Description Framework
      [W3C.rdf-schema] triple, a specific attribute in a database, etc.

   At least one of these references is necessary to enable automated
   construction and update of catalogues (distributed and centralized)
   and the implementation of resolvers that associate the uniform name
   of a document with its physical location(s).  LEX assumes no
   particular relationship between the originator of the document, its
   publisher, and the implementer of catalogues or resolution services.

1.6.  Use of LEX Names in References

   LEX names can be used in references as an HREF attribute value of the
   hypertext link to the referred document.  This link can be created in
   two ways:

   *  by manually inserting in the referring document the link with the
      uniform name: this is a burdensome procedure, especially for
      documents that are already on-line;

   *  by automatically constructing (either permanently or temporarily)
      the link with the uniform name, through reference parsers of a
      text: this is a more time-saving procedure even if subject to a
      certain percentage of errors, since references are not always
      accurate or complete.  This solution could nevertheless be
      acceptable for already published documents.

   Whatever method is adopted, new documents produced in whatever format
   (for example XML, XHTML, etc) should express references through the
   uniform name of the document referred to.

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1.7.  Definitions

   The following terms are used in these specifications:

   *  Source of Law: a general concept to refer to legislation, case
      law, regulations and administrative acts.  In its broadest sense,
      the source of law is anything that can be conceived as the
      originator of 'erga omnes' legal rules.  In this document "Source
      of Law" refers also to acts during their making such as bills that
      might or might not become laws;

   *  Jurisdictional Registrar: an organization that shares and defines
      in any jurisdiction the assignment of the main components of the
      resource identifier through which the identifier uniqueness is
      guaranteed.

1.8.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

1.9.  Syntax Used in this Document

   This document uses the syntax common to many Internet RFCs, which is
   based on the ABNF (Augmented Backus-Naur Form) [RFC5234] meta-
   language.

1.10.  Namespace Registration

   The "lex" namespace has already been registered in the "Formal URN
   Namespaces" registry.

2.  Registration of LEX

2.1.  Identifier Structure

   The identifier has a hierarchical structure as follows:

      "urn:lex:" NSS

   where NSS is the Namespace Specific String composed as follows:

      NSS = jurisdiction ":" local-name

   where:

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   *  jurisdiction identifies the scope (state, regional, municipal,
      supranational or of an organization) where a set of sources of law
      have validity.  It is also possible to represent international
      organizations (either states or public administrations or private
      entities);

   *  local-name is the uniform name of the source of law in the country
      or jurisdiction where it is issued; its internal structure is
      common to the already adopted schemas.  It represents all aspects
      of an intellectual production, from its initial idea, through its
      evolution during the time, to its realisation by different means
      (paper, digital, etc.).

   The jurisdiction element is composed of two specific fields:

      jurisdiction = jurisdiction-code *(";" jurisdiction-unit)

   where:

   *  jurisdiction-code is usually the identification code of the
      country where the source of law is issued.
      To facilitate the transparency of the name, the jurisdiction-code
      follows usually the rules of identification of other Internet
      applications, based on domain name (for details and special cases
      see Section 2.2).
      Due to the differences in representation in the various languages
      of a country, for an easier identification of the country the use
      the standard [ISO3166-1] is strongly RECOMMENDED.
      Therefore a urn-lex ID always begins with a sequence of ASCII
      characters: "urn:lex:ccTLD".  For all the other components that
      follow the jurisdiction-code, the Jurisdictional Registrar decides
      the mode of representation (ASCII or UTF-8 %-encoding) (see
      Section 3.4).
      Where applicable, the domain name of the country or multinational
      or international organisation is used.
      If such information is not available for a particular institution,
      a specific code will be defined (see Section 2.2).  Examples
      reported in this document are hypothetical and assume that the
      corresponding domain name is used for the jurisdiction-code.

   *  jurisdiction-unit are the possible administrative hierarchical
      sub- structures defined by each country or organisation within
      their specific legal system.  This additional information can be
      used in case two or more levels of legislative or judicial
      production exist (e.g., federal, state and municipality level) and
      the same bodies may be present in each jurisdiction.  Therefore
      acts of the same type issued by similar authorities in different
      areas differ for the jurisdiction-unit specification.

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      An example can be the following:
      "br:governo:decreto" (decree of federal government),
      "br;sao.paulo:governo:decreto" (decree of SU+00E3o Paulo state)
      "br;sao.paulo;campinas:governo:decreto" (decree of Campinas
      municipality).

   Examples (hypothetical) of sources of law identifiers are:

   urn:lex:it:stato:legge:2003-09-21;456
       (Italian act)
   urn:lex:fr:etat:loi:2004-12-06;321
       (French act)
   urn:lex:es:estado:ley:2002-07-12;123
       (Spanish act)
   urn:lex:ch;glarus:regiere:erlass:2007-10-15;963
       (Glarus Swiss Canton decree)
   urn:lex:eu:commission:directive:2010-03-09;2010-19-EU
       (EU Commission Directive)
   urn:lex:us:supreme.court:decision:1978-04-28;77-5953
       (US SC decision: Riley vs Illinois)
   urn:lex:be:conseil.etat:decision:2008-07-09;185.273
       (Decision of the Belgian Council of State)

2.2.  Jurisdiction-code Register

   It is planned to create a new registry for jurisdiction-code, with
   the following format:

   *  jurisdiction-code: the identifier of jurisdiction, assigned to the
      country or organisation;

   *  jurisdiction: the official name of the jurisdiction, country or
      organisation;

   *  registrant: essential information to identify the organization
      that requested the registration of the code.  The registrant will
      be responsible for its DNS zone and for the attribution of sub-
      zone delegations, and so on.  It is RECOMMENDED that each
      jurisdiction create a registry of all delegated levels so that the
      organization responsible of each sub-zone can easily be
      identified;

   *  reference: a reference to the defining document (if any).

   The table is initially empty.  Possible example entries are:

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   "br"; "Brazil"; "Prodasen, Federal Senate, address, contact";
         \[reference\]
   "eu"; "European Union"; "DG Digit, European Commission, address,
         contact"; \[reference\]
   "un.org"; "United Nations"; "DPI, United Nations, address,
             contact"; \[reference\]

   CNR is responsible for the jurisdiction-code and the root lex-
   nameserver registries of the resolution routing.

   A new Jurisdictional Registrar will contact CNR or the Designated
   Expert(s) according to the established rules of governance (published
   in the CNR website dedicated to the LEX governance).  The application
   will be evaluated according to the Jurisdictional Registrar
   authoritativeness and the offered guarantees.  The Designated
   Expert(s) will evaluate such applications, with a similar approach as
   of the DNS.  Typically such applications should come from public
   administrations, as authorities enacting sources of law.

   The adopted registration policy is similar to that of the "Expert
   Review" as specified in [RFC8126].  Designated Experts will assign
   jurisdiction codes based on the following principles:

   *  If a request comes from a jurisdiction that corresponds to a
      country and the jurisdiction code is the same as a top level
      ccTLD, then the top level ccTLD should be used as the jurisdiction
      code;

   *  If a request comes from a jurisdiction that corresponds to a
      multi- national (e.g., European Union) or international (e.g.,
      United Nations, World Trade Organization) organizations the Top
      Level Domain Name (e.g., "eu") or the Domain Name (e.g., "un.org",
      "wto.org") of the organization should be used as the jurisdiction
      code;

   *  in case when such multi-national or international organization
      does not have a registered domain, Designated Expert(s) should
      assign something like name.lex.arpa, where name will be the
      acronym of the organization name, in the language chosen by the
      organization itself.  For example, the jurisdiction code of the
      European Economic Community could be "eec.lex.arpa".  Anyway the
      alias mechanism allows to have acronyms in different languages.

   Jurisdiction codes MUST NOT be renamed, because that would violate
   rules that URN assignments are persistent.

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   Jurisdiction codes MUST NOT ever be deleted.  They can only be marked
   as "obsolete", i.e. closed for new assignments within the
   jurisdiction.  Requests to obsolete a jurisdiction code are also
   processed by Designated Expert.

   Designated Expert(s) can unilaterally initiate allocation or
   obsolescence of a jurisdiction code.

   Request for new jurisdiction code assignment must include the
   organization or country requesting it and Contact information (email)
   of who requested the assignment.

2.3.  Conformance with URN Syntax

   The "lex" NID syntax conforms to [RFC8141].  However, a series of
   characters are reserved to identify elements or sub-elements, or for
   future extensions of the LEX naming convention (see Section 3.2).

2.4.  Validation Mechanism

   The Jurisdictional Registrar (or those it delegates) of each adhering
   country or organization is responsible for the definition or
   acceptance of the uniform name's primary elements (issuing authority
   and type of legal measure).

2.5.  Scope

   Global interest.  In fact each body that enacts sources of law can
   identify them by this scheme.  Furthermore, other bodies (even not
   enacting sources of law, such as newspaper or magazine publishers,
   etc.) aiming to refer legal documents, can unequivocally identify
   them by this scheme.

3.  General Syntax and Features of the LEX Identifier

   This section lists the general features applicable to all
   jurisdictions.

3.1.  Allowed and Not Allowed Characters

   These characters are defined in accordance with the [RFC8141]
   "Uniform Resource Names (URNs)".  For various reasons, later
   explained, in the "lex" NSS only a subset of characters is allowed.
   All other characters are either eliminated or converted.

   For the full syntax of the uniform names in the "lex" space, please
   see Section 8.

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3.2.  Reserved Characters

   The following characters are reserved in the specific "lex"
   namespace:

   "@" separator of the expression, that contains information on
       version and language;
   "$" separator of the manifestation, that contains information on
       format, editor, etc.;
   ":" separator of the main elements of the name at any entity;
   ";" separator of level. It identifies the introduction of an element
       at a hierarchically lower level, or the introduction of a
       specification;
   "+" separator of the repetitions of an entire main element (e.g.,
       multiple authorities);
   "|" separator between different formats of the same element (e.g.,
       date);
   "," separator of the repetitions of individual components in the main
       elements, each bearing the same level of specificity (e.g.,
       multiple numbers);
   "~" separator of the partition identifier in references (e.g.,
       paragraph of an article);
   "*" and "!" are reserved for future expansions.

   To keep backward compatibility with existing applications in some
   jurisdictions, the "lex" NID syntax does not include the use of the
   character "/" in this version.
   This character is always converted into "-", except in the formal
   annexes (see Section 6.4.1).

3.3.  Case Sensitivity

   For all the languages where different cases (upper or lower cases) or
   different spelling of the same word are possible, names belonging to
   "lex" namespace are case-insensitive.  It is RECOMMENDED that, in
   latin alphabet, they be created in lower case, but names that differ
   only in case, or in the spelling, of the same word MUST be considered
   to be equivalent.
   (e.g., "Ministry" will be recorded as "ministry").

3.4.  Unicode Characters outside the ASCII Range

   In order to exploit DNS as a routing tool towards the proper
   resolution system, to keep editing and communication more simple and
   to avoid character percent-encoding, it is RECOMMENDED that the
   characters outside the ASCII range (e.g. national characters,
   diacritic signs, ...) are turned into base ASCII characters (e.g.,
   the Italian term "sanitU+00E0" replaced into "sanita", the French

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   term "ministU+00E8re" replaced into "ministere"), in case by
   transliteration (e.g.  "MU+00FCnchen" replaced into "muenchen").

   This mapping consists of:

   *  transcription from non-Latin alphabets;

   *  transliteration of some signs (diaeresis, eszett, ...);

   *  preservation of the only basic characters, eliminating the signs
      placed above (accents, tilde, ...), below (cedilla, little tail,
      ...) or on (oblique cut, ...).

   The most suitable, well-known and widespread mapping system for a
   given language MUST be chosen by the jurisdiction, or, in agreement
   with this one, by the jurisdiction-unit in case of different
   languages in the various regions, also taking into account the
   choices made for the same language by other jurisdictions.
   Certainly this mapping is simpler and more feasible for languages
   that use the Latin alphabet and gradually becomes more complex both
   for other alphabets and for writing systems with opposite orientation
   (from right to left) or based on ideographic symbols.

   If this conversion is not acceptable by a specific jurisdiction or it
   is not available in a given language, UNICODE MUST be used and, for
   accessing network protocols, any UNICODE code points outside the
   ASCII range MUST be converted in UTF-8 %-encoding according to
   [RFC3986] and [RFC3629].
   In this case it should be noted that the generated URN (as some of
   its parts) cannot be used directly for routing through DNS, and
   therefore the jurisdiction must adopt one of the following
   strategies:

   *  to convert non-ASCII characters within the DNS into the IDN
      encoding, using the [RFC5894] punycode translation (e.g.
      mU+00FCnchen in xn--mnchen-3ya), and to develop an interface
      software that converts the URN before the navigation in DNS, or

   *  to create a routing service relying on a software, out of DNS,
      addressing a proper resolution service.

   Note that the urn:lex ID, could contain groups of characters (UTF-8
   %-encoded) of some languages with different orientations: in this
   case the BiDi rules apply [RFC5893].

   Summarizing, the preference order is the following:

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   *  Conversion into basic ASCII, RECOMMENDED solution (for not having
      to make conversions for network protocols and DNS);

   *  Using UNICODE, and connvert into UTF-8 %-encoding [RFC3629], for
      accessing network protocols, and to punycode [RFC5894], only for
      navigation in DNS, via software interface;

   *  Creation of a routing service relying on a software, out of DNS,
      addressing a proper resolution service.

   The first solution allows native DNS routing, while the other two
   require software development for the interface or the routing.
   However it is up to the specific jurisdiction to choose the preferred
   solution.

   Two examples (Latin and Cyrillic alphabet) relating to the different
   solutions adopted are here reported:

   a circular adopted by the Municipality of Munich (Rundschreiben der
     Stadt MU+00FCnchen):
   - ascii = urn:lex:de:stadt.munchen:rundschreiben:...
   - unicode = urn:lex:de:stadt.mU+00FCnchen:rundschreiben:...
   - utf-8 = urn:lex:de:stadt.m%xC3%xBCnchen:rundschreiben:...
   - punycode = urn:lex:de:stadt.xn--mnchen-3ya:rundschreiben:...

   a state law of the Russian Federation (latin: gosudarstvo zakon;
     cyrillic: U+0441U+043EU+0441U+0442U+043EU+044FU+043DU+0438U+0435
     U+0437U+0430U+043AU+043EU+043D):
   - ascii = urn:lex:ru:gosudarstvo:zakon:...
   - unicode = urn:lex:ru:U+0441U+043EU+0441U+0442U+043EU+044FU+043D
               U+0438U+0435:U+0437U+0430U+043AU+043EU+043D:...
   - utf-8 = urn:lex:ru:%xD1%x81%xD0%xBE%xD1%x81%xD1%x82%xD0%xBE%xD1
             %x8F%xD0%xBD%xD0%xB8%xD0%xB5:%xD0%xB7%xD0%xB0%xD0%xBA
             %xD0%xBE%xD0%xBD:...
   - punycode = urn:lex:ru:xn--80aebe3cdmfdkg:xn--80ankme:...

   assuming that the Russia jurisdiction-code is expressed
   in ASCII ("ru"),
   while the Cyrillic version ("U+0440U+0444") has the
   puny-code "xn--p1ai".

3.5.  Abbreviations

   Abbreviations are often used in law for indicating institutions (e.g.
   Min.), structures (e.g.  Dept.), or legal measures (e.g.  Reg.) but
   not in a uniform way, therefore their expansion is highly
   RECOMMENDED. (e.g., "Min." is reported as "ministry")

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3.6.  Date Format

   The [ISO.8601.1988] is the international format for representing
   dates: therefore dates MUST always be represented in this format (4
   digits for the year, 2 digits for the month, 2 digits for the day):

       date-iso = yyyy-mm-dd

   (e.g., "September 2, 99" will be written as "1999-09-02").

   This format ensures interoperability between different representation
   systems and there are several programs for mapping other formats to
   this one.
   However, to make reading and understanding such other formats (e.g.
   Jewish calendar), the urn:lex scheme provides that the date can be
   added in the jurisdiction's own format
   (e.g. the date in the previous example would be 21.Elul,5759, that
   is:

   - in Hebrew characters:
     "U+05DBU+05F4U+05D0.U+05D0U+05B1U+05DCU+05D5U+05BCU+05DC.U+05EA
      U+05E9U+05E0U+05F4U+05D8";
   - in UTF-8 code:
     "%x5c%x75%x30%x35%x44%x42%x5c%x75%x30%x35%x46%x34%x5c%x75%x30%x35
      %x44%x30%x2e%x5c%x75%x30%x35%x44%x30%x5c%x75%x30%x35%x42%x31%x5c
      %x75%x30%x35%x44%x43%x5c%x75%x30%x35%x44%x35%x5c%x75%x30%x35%x42
      %x43%x5c%x75%x30%x35%x44%x43%x2e%x5c%x75%x30%x35%x45%x41%x5c%x75
      %x30%x35%x45%x39%x5c%x75%x30%x35%x45%x30%x5c%x75%x30%x35%x46%x34
      %x5c%x75%x30%x35%x44%x38").

   Therefore, for all the dates in the urn:lex identifier (see
   Section 6.3 and Section 7.1.2), it is also possible to indicate the
   one in the local format:

       date = date-iso [ "|" date-loc ]

   (e.g., "September 2, 99" will be written in ISO plus Hebrew format as
   "1999-09-02|U+05DBU+05F4U+05D0.U+05D0U+05B1U+05DCU+05D5U+05BCU+05DC.
   U+05EAU+05E9U+05E0U+05F4U+05D8").

   The characters which are not allowed (e.g. "/") or which are reserved
   (e.g. ",") cannot exist inside the date-loc and therefore MUST be
   turned into ".".

4.  Specific Syntax and Features of the LEX Identifier

   In this section there are other features related to specific
   jurisdictions and the implementation of which is RECOMMENDED.

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4.1.  Spaces, Connectives and Punctuation Marks

   All the language connectives (e.g., articles, prepositions, etc.),
   the punctuation marks and all the special characters (as apostrophes,
   dashes, etc.), when explicitly present, are eliminated (no
   transformation occurs in cases of languages with declensions or
   agglutinating languages).  The words left are connected to each other
   by a dot (".") which substitutes the "space".
   (e.g., "Ministry of Finances, Budget and of Economic Planning"
   becomes "ministry.finances.budget.economic.planning";
   "Ministerstvo Finansov" becomes "ministerstvo.finansov")

4.2.  Acronyms

   The use of acronyms might be confusing and encourage ambiguity in
   uniform names (the same acronym may indicate two different
   institutions or structures), therefore their expansion is highly
   RECOMMENDED.
   (e.g., "FAO" is expanded as "food.agriculture.organization")

4.3.  Ordinal Numbers

   To even the representation, it is highly RECOMMENDED that any ordinal
   number included in a component of a document name (e.g., in the
   description of an institution body) is indicated in Western Arabic
   numerals, regardless to the original expression: whether in Roman
   numerals, or with an adjective, or in Arabic numeral with apex, etc.
   (IV, third, 1U+00B0, 2^, etc.).
   (e.g., "Department IV" becomes "department.4")

5.  Creation of the Source of Law LEX Identifier - Baseline structure

5.1.  Basic Principles

   The uniform name must identify one and only one document (more
   precisely a "bibliographic resource" [ISBD], see also Section 5.2)
   and is created in such a way that it is:

   *  self-explanatory ;

   *  identifiable through simple and clear rules;

   *  compatible with the practice commonly used for references;

   *  able to be created from references in the text, automatically (by
      parser) or manually;

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   *  representative of both the formal and the substantive aspects of
      the document.

5.2.  Model of Sources of Law Representation

   According to the [FRBR] (Functional Requirements for Bibliographic
   Records) model developed by IFLA (International Federation of Library
   Associations and Institutions), in a source of law, as in any
   intellectual production, four fundamental entities (or aspects) can
   be specified.

   The first two entities reflect its contents:

   *  work: identifies a distinct intellectual creation; in our case, it
      identifies a source of law both in its original form as amended
      over time;

   *  expression: identifies a specific intellectual realisation of a
      work; in our case it identifies every different (original or up-
      to- date) version of the source of law over time and/or language
      in which the text is expressed.

   The other two entities relate to its form:

   *  manifestation: identifies a physical embodiment of an expression
      of a work; in our case it identifies embodiments in different
      media (printing, digital, etc.), encoding formats (XML, PDF,
      etc.), or other publishing characteristics;

   *  item: identifies a specific copy of a manifestation; in our case
      it identifies individual physical copies as they are found in
      particular physical locations.

   In this document the [FRBR] model has been interpreted for the
   specific characteristics of the legal domain.  In particular, apart
   from the language that does produce a specific expression, the
   discriminative criterion between expression and manifestation is
   based on the difference of the juridical effects that a variation can
   provide with respect to the involved actors (citizens, parties,
   institutions).  In this scenario the main characteristic of the
   expression of an act is represented by its validity over the time,
   during which it provides the same juridical effects.  These effects
   may change as a result of amendments or annulments of other
   legislative or jurisprudential acts.  Therefore notes,
   summarizations, comments, anonymizations and other editorial
   activities over the same text do not produce different expressions,
   but different manifestations.

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5.3.  The Structure of the Local Name

   The local-name within the "lex" namespace MUST contain all the
   necessary pieces of information enabling the unequivocal
   identification of a legal document.  If the local-name violates this
   requirement, the related URN is not a valid one within the "lex"
   namespace.

   In the legal domain, at "work" level, three components are always
   present: the enacting authority, the type of provision and the
   details.  A fourth component, the annex, can be added if any.  It is
   often necessary to differentiate various expressions, that is:

   *  the original version and all the amended versions of the same
      document;

   *  the versions of the text expressed in the different official
      languages of the state or organization.

   Finally the uniform name allows a distinction among diverse
   manifestations, which may be produced by multiple publishers using
   different means and formats.

   In every case, the basic identifier of the source of law (work)
   remains the same, but information is added regarding the specific
   version under consideration (expression); similarly a suffix is added
   to the expression for representing the characteristics of the
   publication (manifestation).

   Information that forms a source of law uniform name at each level
   (work, expression, manifestation) is expressed in the official
   language of the relevant jurisdiction; in case of multiple official
   languages (as in Switzerland) or more involved jurisdictions (as in
   international treaties), more language-dependent names (aliases) are
   created.

   Therefore, the more general structure of the local name appears as
   follows:

          local-name = work ["@" expression] ["$" manifestation]

   However, consistent with legislative practice, the uniform name of
   the main original provision (work) becomes the identifier of an
   entire class of documents which includes: the original main document,
   the annexes, and all their versions, languages and formats
   subsequently generated.

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5.4.  Structure of the Document Identifier at "Work" Level

   The structure of the document identifier is comprised of the four
   fundamental elements mentioned above, distinguished one from the
   other ordered by increasingly narrow domains and competencies:

      work = authority ":" measure ":" details *(":" annex)

   where:

   *  authority is the issuing or proposing authority of the measure
      (e.g., State, Ministry, Municipality, Court, etc.);

   *  measure is the type of the measure, both public nature (e.g.,
      constitution, act, treaty, regulation, decree, decision, etc.) as
      well as private one (e.g., license, agreement, etc);

   *  details are the terms associated to the measure, typically the
      date (usually the signature date) and the number included in the
      heading of the act;

   *  annex is the identifier of the annex, if any (e.g., Annex 1).

   In case of annexes, both the main document and its annexes have their
   own uniform name so that they can individually be referenced; the
   identifier of the annex adds a suffix to that of the main document.
   In similar way the identifier of an annex of an annex adds an ending
   to that of the annex which it is attached to.

   The main elements of the work name are generally divided into several
   elementary components, and for each component, specific rules of
   representation are established (criteria, modalities, syntax and
   order).  For the details regarding each element, please see the
   Section 6.  Examples (hypothetical) of work identifiers are:

   urn:lex:it:stato:legge:2006-05-14;22
   urn:lex:uk:ministry.justice:decree:1999-10-07;45
   urn:lex:ch;glarus:regiere:erlass:2007-10-15;963
   urn:lex:es:tribunal.supremo:decision:2001-09-28;68
   urn:lex:fr:assemblee.nationale:proposition.loi:13.legislature;1762
   urn:lex:br:estado:constituicao:1988-10-05;lex-1
   urn:lex:un.org:united.nations;general.assembly:resolution:
       1961-11-28;a-res-1661
   urn:lex:nl:hoge.raad:besluit:2008-04-01;bc8581

   The type of measure is important to identify case law, as well as
   legislation, especially within the legal systems where cases are
   identified traditionally only through the year of release and a

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   number.  Since the aim of the lex schema is to identify specific
   materials, the type of measure or the full date are able to
   differentiate between materials belonging to a specific case.

   Here below is an example where the type of measure or the full date
   are essential for identify specific materials of a case:

   - 4/59 Judgment of the EEC Court of Justice 04/04/1960, Mannesmann
     AG and others / ECSC High Authority
     urn:lex:eec.lex.arpa:court.justice:judgement:1960-04-04;4-59
   - 4/59 Order of the EEC Court of Justice 18/05/1960, Mannesmann AG
     and others / ECSC High Authority
     urn:lex:eec.lex.arpa:court.justice:order:1960-05-18;4-59

5.5.  Aliases

   International treaties involve multiple signatory jurisdictions, and
   are therefore represented through multiple identifiers, each of them
   related to a signatory.  For example, a bilateral France and Germany
   treaty is identified through two URNs (aliases) belonging to either
   "fr" or "de" jurisdiction
   (e.g., "urn:lex:fr:etat:traite:..." and
   "urn:lex:de:staat:vertrag:...") since it pertains to both the French
   and the German jurisdiction.

   In the states or organisations that have multiple official languages,
   a document has multiple identifiers, each of them expressed in a
   different official language, basically a set of equivalent aliases.
   This system permits manual or automated construction of the uniform
   name of the referred source of law in the same language used in the
   document itself.
   (e.g., "urn:lex:eu:council:directive:2004-12-07;31",
   "urn:lex:eu:consiglio:direttiva:2004-12-07;31", etc.)

   Moreover, a document can be assigned more than one uniform name in
   order to facilitate its linking from other documents.  This option
   can be used for documents that, although unique, are commonly
   referenced from different perspectives.  For example, the form of a
   document's promulgation and its specific content (e.g., a Regulation
   promulgated through a Decree of the President of the Republic).

5.6.  Structure of the Document Identifier at "Expression" Level

   There may be several expressions of a legal text, connected to
   specific versions or languages.

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   Each version is characterized by the period of time during which that
   text is to be considered to be in force or effective.  The lifetime
   of a version ends with the issuing of the subsequent version.  New
   versions of a text may be brought into existence by:

   *  amendments due to the issuing of other legal acts and to the
      subsequent production of updated or consolidated texts;

   *  correction of publication errors (rectification or errata
      corrige);

   *  entry into or departure from a particular time span, depending on
      the specific date in which different partitions of a text come
      into force.

   Each such version may be expressed in more than one language, with
   each language-version having its own specific identifier.  The
   identifier of a source of law expression adds such information to the
   work identifier, using the following main structure:

       expression = version [":" language]

   where:

   *  version is the identifier of the version of the original or
      amended source of law.  In general it is expressed by the
      promulgation date of the amending act; other specific information
      can be used for particular documents.  If necessary, the original
      version is specified by the string "original", expressed in the
      language of the act or version (for the details regarding this
      element, please see the Section 7);

   *  language is the identification code of the language in which the
      document is expressed, according to [RFC5646] (it=Italian,
      fr=French, de=German, etc.).  The granularity level of the
      language (for example the specification of the German language as
      used in Switzerland rather than the standard German) is left to
      each specific jurisdiction.  The information is not necessary when
      the text is expressed in the sole official language of the country
      or jurisdiction.

   Hypothetical examples of document identifiers for expressions are:

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   urn:lex:ch:etat:loi:2006-05-14;22@originel:fr
       (original version in French)
   urn:lex:ch:staat:gesetz:2006-05-14;22@original:de
       (original version in German)
   urn:lex:ch:etat:loi:2006-05-14;22@2008-03-12:fr
       (amended version in French)
   urn:lex:ch:staat:gesetz:2006-05-14;22@2008-03-12:de
       (amended version in German)
   urn:lex:be:conseil.etat:decision:2008-07-09;185.273@originel:fr
       (original version in French of a Belgian decision)

5.7.  Structure of the Document Identifier at "Manifestation" Level

   To identify a specific manifestation, the uniform name of the
   expression is followed by a suitable suffix containing the following
   main elements:

   *  editor: editorial staff who produced it, expressed according to
      its Internet domain name.  Since publishers' domain names may vary
      over time, manifestations already assigned by a publisher remain
      unchanged even if the identified object is no longer accessible.
      In this case, in order to make its materials accessible, the
      publisher will have to create for each of them a new manifestation
      with the new domain name;

   *  format: the digital format (e.g., XML, HTML, PDF, etc.) expressed
      according to the MIME Content-Type standard [RFC2045], where the
      "/" character is to be substituted by the "-" sign;

   *  component: possible components of the expressions contained in the
      manifestation.  Such components are expressed by language-
      dependent labels representing the whole document (in English
      "all") or the main part of the document (in English "body") or the
      caption label of the component itself (e.g.  Table 1, Figure 2,
      etc.);

   *  feature: other features of the document (e.g., anonymized decision
      text).

   The manifestation suffix thus reads:

       manifestation = editor ":" format
                       [":" component [":" feature]]

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   To indicate possible features or peculiarities, each main element of
   the manifestation MAY be followed by further specifications
   (separated by ";"), for example as regards editor the archive name
   and the electronic publisher, for format the version, etc.  Therefore
   the main elements of the manifestation will assume the forms:

       editor = publisher *(";" specification)
       format = mime *(";" specification)
       component = part *(";" specification)
       feature = attribute *(";" specification)

   The syntax details of the manifestation element is shown in
   Section 8, in the related part.

   (examples (hypothetical):

   the original version of the Italian act 3 April 2000, n. 56 might
   have the following manifestations with their relative uniform names:

   - PDF format (vers. 1.7) of the whole act edited by the Italian
     Parliament:
     "urn:lex:it:stato:legge:2000-04-03;56$application-pdf;
     1.7:parlamento.it"
   - XML format (version 2.2 DTD NIR) of the text of the act and PDF
     format (version 1.7) of the "Figura 1" (figure 1) contained in the
     body, edited by the Italian Senate:
     "urn:lex:it:stato:legge:2000-04-03;56$text-xml;dtd-nir-2.2:
     senato.it:testo"
     "urn:lex:it:stato:legge:2000-04-03;56$application-pdf;1.7:
     senato.it:figura.1"

   the Spanish URN of the html format of the whole Judgment of the
   European Court of Justice n. 33/08 of 11/06/2009, in Spanish version,
   published in the Jurifast database in anonymized form:

   "urn:lex:eu:tribunal.justicia:sentencia:2009-06-11;33-08
   @original:es$text-html:juradmin.eu;jurifast:todo:anonimo")

   It is useful to be able to assign a uniform name to a manifestation
   (or to a part of it) in case non-textual objects are involved.  These
   may be multimedia objects that are non-textual in their own right
   (e.g. geographic maps, photographs, etc.), or texts recorded in non-
   textual formats, such as image scans of documents.

5.8.  Sources of Law References

   References to sources of law often refer to specific partitions of
   the act (article, paragraph, etc.) and not to the entire document.

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   From a legal point of view, a partition is always a text block, that
   represents a logical subdivision of an act.

   As regards the digital representation, a partition is represented by
   an element (a block of text) with its own ID; this ID aims to
   identify the related element and to locate it.  In this case,
   therefore, it is possible either to extract or to point to a
   partition.

   In a mark-up not fitting the logical structure of the text (as HTML),
   generally only the starting point of the partition, rather than the
   whole block of text or element, is identified through a label (a <a
   id=partitionID></a> tag in Html Markup Language [W3C.HTML]).  In this
   case therefore it is not possible to extract a partition but only to
   point to it.

   Partitions should be assigned unique labels or IDs within the
   including document and their value should be the same regardless of
   document format.

   For enabling the construction of the partition identifier between
   different collections of documents, specific construction rules for
   IDs or labels will be defined and shared, within each country or
   jurisdiction, for any document type
   (e.g., for legislation, the paragraph 2 of the article 3 might have
   as label or ID the value "art3;par2", similarly for case-law,
   paragraph 22 of the judgment in Case 46/76 Bauhuis v Netherlands,
   might have as label or ID the value "par22").

   Furthermore, it is useful to foresee the compatibility with
   applications able to manage this information (e.g., returning the
   proper element); these procedures are particularly useful in the case
   of rather long acts, such as codes, constitutions, regulations, etc.
   For this purpose it is necessary that the partition identifier is
   transmitted to the servers (resolution and application) and therefore
   it cannot be separated by the typical "#" character of URI fragment,
   which is not transmitted to the server.

   According to these requirements, the syntax of a reference is:

        URN-reference = URN-document ["~" partition-id]

   (e.g., to refer to the paragraph 3 of the article 15 of the French
   Act of 15 May 2004, n. 106, the reference can be
   "urn:lex:fr:etat:loi:2004-05-15;106~art15;par3").

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   Using a different separator ("~") from the document name, the
   partition ID is not withheld by the browser but it is transmitted to
   the resolution process.  This enables the resolver to retrieve (for
   example, out of a database) only the referred partition, if the
   partition syntax is compatible with the media type used, otherwise to
   return the whole act.

   When resolving to HTTP, the resolver SHALL transform the partition ID
   to an appropriate internal reference (#) in the page, or at the
   beginning if that point cannot be found.  The transformation in URI
   fragment is obtained appending to the URL the "#" character followed
   by the partition ID (in the example above, the returned URL will be
   <URL-document>#art15;par3).  Doing this, knowing the granularity of
   the act markup, the resolver could exploit the hierarchical structure
   of the ID, eliminating sub- partitions not addressed.  If only the
   article was identified in the act, in the previous example it could
   return <URL-document>#art15 only.

   It is possible to use the general syntax (with "#"); in this case
   only the URN document component of the reference is transmitted to
   the resolver, therefore the whole document will be always retrieved.

6.  Specific Syntax of the Identifier at "Work" Level

6.1.  The authority Element

6.1.1.  Indication of the Authority

   The authority element of a uniform name may indicate, in the various
   cases:

   *  the actual authority issuing the legal provision.  More
      specifically, the authority adopting the provision or enacting it;

   *  the institution where the provision is registered, known and
      referenced to, even if produced by others (e.g., the bills
      identified through the reference to the Chamber where they are
      presented);

   *  the institution regulated (and referred to in citations) by the
      legal provision even when this is issued by another authority
      (e.g., the statute of a Body);

   *  the entity that proposed the legal material not yet included in
      the institutional process (e.g. a proposed bill written by a a
      political party).

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6.1.2.  Multiple Issuers

   Some sources of law are enacted by a number of issuing parties (e.g.,
   inter-ministerial decrees, agreements, etc.).  In this case, the
   authority element contains all the issuing parties (properly
   separated), as follows:

      authority = issuer *("+" issuer)

   (e.g., "ministry.justice+ministry.finances")

6.1.3.  Indication of the Issuer

   Each issuing authority is essentially represented by either an
   institutional office (e.g., Prime Minister) or an institution (e.g.,
   Ministry); in the last case, the authority is indicated in accordance
   with the institution's hierarchical structure, from the more general
   to more specific (Council, Department, etc.), ending with the
   relative office (President, Director, etc.).  Therefore, the
   structure of the issuer is as follows:

      issuer = (institution *(";" body-function)) / office

   (e.g., "ministry.finances;department.revenues;manager")

6.1.4.  Indication of the Body

   Depending on the kind of measure, the body within the issuing
   authority is unambiguously determined (e.g., the Council for Regional
   Acts) and normally it is not indicated in the references.  Just like
   in practice, the indication of the enacting authority is limited to
   the minimum in relation to the type of measure.
   (e.g., "region.tuscany:act" and not "region.tuscany;council:act")

6.1.5.  Indication of the Function

   Generally, the function is indicated, sometimes instead of the body
   itself:

   *  in case of political, representative or elective offices
      (e.g., "university.oxford;rector:decree" instead of
      "university.oxford;rectorship:decree");

   *  when it refers to a top officer in the institution (e.g., general
      manager, general secretary, etc.) which is not always possible to
      associate a specific internal institutional structure to
      (e.g., "national.council.research;general.manager").

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   It is not indicated when it clearly corresponds to the person in
   charge of an institution (typically, a general director); in this
   case, only the structure and not the person in charge is indicated
   (e.g., "ministry.justice;department.penitentiary.administration").

   The function MUST be indicated when:

   *  it is not the same of the director or the person in charge of the
      structure (for example, in case of an undersecretary, a deputy
      director, etc.);

   *  the type of measure may be both monocratic or collegial: the
      indication of the office eliminates the ambiguity.

6.1.6.  Conventions for the Authority

   Acts and measures bearing the same relevance as an act, issued or
   enacted since the foundation of the State, have conventionally
   indicated "state" (expressed in each country official language) as
   authority; the same convention is used for constitutions, codes
   (civil, criminal, civil procedure, criminal procedure, etc) and
   international treaties.

6.2.  The measure Element

6.2.1.  Criteria for the Indication of the Type of Measure

   In uniform names the issuing authority of a document is mandatory.
   This makes unnecessary to indicate any further qualification of the
   measure (e.g., ministerial decree, directorial ordinance, etc.), even
   if it is widely used.  When the authority-measure combination clearly
   identifies a specific document, the type of measure is not defined
   through attributes referring to the enacting authority.
   (e.g., "region.tuscany:act" and not "region.tuscany:regional.act")

6.2.2.  Further Specification to the Type of Measure

   In the measure element, it is usually sufficient to indicate the type
   of a measure.  As usual, references to sources of law, rather than
   through the formal details (date and number), may be made through
   some of their characteristics such as the subject-matter covered
   (e.g., accounting regulations), nicknames referring to the promoter
   (e.g., Bassanini Act) or to the topic of the act (e.g., Bankruptcy
   Law), etc.. In these cases, the type of measure MAY be followed by
   further specifications useful in referencing even if the details are
   lacking:

         measure = measure-type *(";" specification)

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   (e.g., "regulations;accounting" or "act;bankruptcy")

6.2.3.  Aliases for Sources of Law with Different Normative References

   There are legislative measures that, although unique, are usually
   cited in different ways, for example through the legislative act
   introducing them into the legal order (President's decree,
   legislative decree, etc.) or through their legislative category
   (regulations, consolidation, etc.).  In order to ensure, in all the
   cases, the validity of the references, an alias (additional URN LEX
   identifier), that takes into account the measure category, is added
   to what represents the legislative form of the same act.
   (e.g., "state:decree.legislative:1992-07-24;358" and
   "state:consolidation;public.contracts:1992-07-24;358").

6.2.4.  Relations between Measure and Authority in the Aliases

   The sources of law including different normative references are
   usually introduced in legislation through the adoption or the issuing
   of an act, which they are either included or attached to.  It is,
   therefore, necessary to create an alias linking the two aspects of
   the same document.  Specifically, the different measures can be:

   *  adopted/issued by an authority different from the one regulated by
      the provision (e.g., the statute of a Body); in this case, the
      correlation is established between two uniform names each
      featuring a completely different authority element
      (e.g., "italian.society.authors.publishers:statute" and
      "ministry.cultural.activities+ministry.finances.budget.economic.
      planning:decree");

   *  issued by the institution itself either because it has issuing
      authority or by virtue of a proxy (e.g., a provision that refers
      to the functioning of the Body itself); in this case, the two
      aliases share the first part of the authority;
      (e.g., "municipality.firenze:statute" and
      "municipality.firenze;council:deliberation");

   *  issued by the same Body to regulate a particular sector of its own
      competence; in this case the authority element is the same
      (e.g., "ministry.justice:regulation;use.information.tools.
      telematic.process" and "ministry.justice:decree").

6.3.  The Details Element

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6.3.1.  Indication of the Details

   The details of a source of law usually include the date of the
   enactment and the identification number (inclusion in the body of
   laws, register, protocol, etc.).

   Some measures can have multiple dates; there are also cases in which
   the number of the measure does not exist (unnumbered measures) or a
   measure has multiple numbers (e.g., unified cases).  For these
   reasons, the set up of both elements (date and number) includes
   multiple values.

   Some institutions (e.g., the Parliaments) usually identify documents
   through their period of reference (e.g., the legislature number)
   rather than through a date, which would be much less meaningful and
   never used in references (e.g., Senate bill S.2544 of the XIV
   legislature).  In these cases, the component period is used in
   substitution of the component dates.

   Usually details of a measure are not reported according to a specific
   sequence; in accordance with the global structure of the uniform
   name, which goes from the general to the specific, the sequence date-
   number has the following form:

       details = (dates / period) ";" numbers

   (e.g., "2000-12-06;126", "14.legislature;s.2544")

6.3.2.  Multiple Dates

   Some sources of law, even if unique, are identified by more than one
   date; in this case, in the field dates all the given dates are to be
   reported and indicated as follows:

   dates = date *("," date)

   (e.g., the measure of the Data Protection Authority of December 30,
   1999- January 13, 2000, No. 1/P/2000 has the following uniform name:
   "personal.data.protection.authority:measure:1999-12-30,2000-01-13;
   1-p-2000").

   As specified in Section 3.6, all the dates can have, in addition to
   the ISO format, also the date typical of the jurisdiction.

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6.3.3.  Unnumbered Measures

   Measures not officially numbered in the publications may have a non-
   unequivocal identifier, because several measures of the same type can
   exist, issued on the same day by the same authority.  To ensure that
   the uniform name is unambiguous, the numbers field MUST, in any case,
   contain a discriminating element, which can be any identifier used
   internally, and not published, by the authority (e.g., protocol).

   If the authority does not have its own identifier, one identifier
   MUST be created for the name system.  In order to easily
   differentiate it, such number is preceded by the string "lex-":

      number-lex = "lex-" 1*DIGIT

   (e.g., "ministry.finances:decree:1999-12-20;lex-3")

   It is responsibility of the authority issuing a document to assign a
   discriminating specification to it; in case of multiple authorities,
   only one of them is responsible for the assignment of the number to
   the document (e.g., the proponent).

   The unnumbered measures published on an official publication (e.g.,
   the Official Gazette), instead of by a progressive number are
   recognized by the univocal identifying label printed on the paper.
   Such an identifier, even if unofficial but assigned to a document in
   an official publication, is to be preferred because it has the clear
   advantage to be public and therefore easier to be found.

6.3.4.  Multiple Numbers

   Some legal documents (e.g., bills), even if unique, are identified by
   a set of numbers (e.g., the unification of cases or bills).  In this
   case, in the numbers field, all the identifiers are reported,
   according to the following structure:

     numbers = document-id *("," document-id)

   (e.g., "2000-06-12;c-10-97,c-11-97,c-12-97")

   The characters which are not allowed (e.g., "/") or reserved (e.g.,
   ":"), including the comma, cannot exist inside the document-id, and
   therefore MUST be turned into "-".

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   Where special characters contained in the number of the act are
   distinctive of the act itself (e.g. bill n. 123-bis (removal of 123)
   and n. 123/bis (return of 123)) and would disappear with the
   conversion to "-", a further ending must be added, allowing to
   distinguish the acts (e.g. bill n.123-bis-removal and 123-bis-
   return).

6.4.  The annex Element

6.4.1.  Formal Annexes

   Although annexes are an integral part of the legal document, they may
   be referred to and undergo amendments separately from the act to
   which they are annexed.  It is, therefore, necessary that both the
   main document as well as each formal individual annex is
   unequivocally identified.

   Formal annexes may be registered as separate parts or together with a
   legal provision; they may also be autonomous in nature or not.  In
   any case, they MUST be given a uniform name, which includes the
   uniform name of the source of law to which they are attached, and a
   suffix which identifies the annex itself.

   The suffix of formal annexes includes the official heading of the
   annex and, possibly, further specifications (e.g., the title) which
   will facilitate the retrieval of the annex in case the identifier is
   missing:

       annex = annex-id *(";" specification)

   (e.g., "region.sicily;council:deliberation:1998-02-12;14:annex.a;
   borders.park")

   The characters which are not allowed (e.g. "/") or which are reserved
   (e.g. ":") must not be featured in the annex-id and therefore MUST be
   turned into ".".

6.4.2.  Annexes of Annexes

   When there are annexes to an annex, their corresponding identifiers
   are created by adding to the identifier of the original annex those
   of the annexes that are connected with it (that is, attached to it).

   (e.g., Table 1 attached to the Annex A of the preceding legal act has
   the following uniform name:
   "region.sicily;council:deliberation:1998-02-12;14:annex.a;
   borders.park:table.1;municipality.territories").

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7.  Specific Syntax of the Version Element of the "Expression"

7.1.  The version Element

7.1.1.  Different Versions of a Legislative Document

   The creation of an updated text of a document may have one of the
   following forms:

   *  "multi-version": when specific mark-ups which identify the
      modified parts of a document (added, substituted or deleted parts)
      and their related periods of effectiveness are indicated inside
      one single object (e.g., an xml file).  Such a document will be
      able, in a dynamic way, to appear in different forms according to
      the requested date of effectiveness.  In this document type,
      usually a set of metadata contains the lifecycle of the document
      (from the original to the last modification), including the
      validity time interval of each version and of each related text
      portion;

   *  "single-version": when, on the contrary, a new and distinct object
      is created for each amendment to the text at a given time.  Each
      object is, therefore, characterized by its own period of validity.
      In any case all the versions SHOULD be linked one another and
      immediately navigable.

   In a "multi-version" document each time interval should have a link
   to the related in-force document version which can be therefore
   displayed.  In a "single-version" document, the metadata should
   contain links to the all the previous modifications and a link only
   to the following version, if any.

   [RFC8288] can be used as reference to establish links between
   different document versions, either in the "multi-version" or in the

   "single-version" document.  According to [RFC8288] the following
   relations are useful:

   *  current (or last or last-version): in-force version

   *  self: this version

   *  next: next version

   *  previous: previous version

   *  first: original version

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   It is RECOMMENDED that these relations are inserted in the header of
   each version (if "single-version") or associated to each entry
   containing a single URN (if "multi-version").

7.1.2.  Identification of the Version

   In order to identify the different time versions of the same act, to
   the uniform name of the original document has to be added a specific
   suffix.

   Such a suffix identifies each version of a legal provision and
   includes, first and foremost, one of the following elements:

   *  the issuing date of the last amending measure taken into account;

   *  the date in which the communication of the rectification or of the
      errata corrige, is published;

   *  a specification which must identify the reason concerning the
      amendment (e.g., the specific phase of the legislative process),
      for the cases in which the date is not usually used (e.g., bills).

   It is possible to add further specifications that will distinguish
   each of the different versions of the text to guarantee identifier
   unequivocalness.  For example with regard to changes of the in-force
   or effectiveness of any partition or portion of the text itself
   (e.g., when the amendments introduced by an act are applied at
   different times) or different events occurring on the same date.

      version = (amendment-date / specification)
                *(";" (event-date / event))

   where:

   *  amendment-date contains the issuing date of the last considered
      amendment or of the last communication of amendment.  In case the
      original text introduces differentiated periods in which an act is
      effective and the information system produces one version for each
      of them, such element contains the string "original" expressed in
      the language of the act or version;

   *  specification any information useful to identify unambiguously and
      univocally the version;

   *  event-date contains the date in which a version is put into force,
      is effective or is published;

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   *  event is a name assigned to the event producing a further version
      (e.g., amendment, decision, etc.).

   The issuing date of an amending act was chosen as identifier of a
   version because it can be obtained from the heading (formal data).

   (e.g., the name "state:royal.decree:1941-01-30;12@1998-02-19"
   identifies the updated text of the "Royal Decree of 30/1/1941, No.
   12" with the amendments introduced by the "Law Decree of 19/2/1998,
   No. 51", without any indication of its actual entry into force.
   The same uniform name with the additional ending ";1999-01-01"
   indicates the in-force or effective version starting in a different
   date (from 1/1/99).

   For a full compatibility, every updating of a text or of the
   effectiveness of a "multi-version" document implies the creation of a
   new uniform name, even if the object remains only one, containing the
   identifier of the virtually generated version, exactly as in the case
   of a "single-version" document.  A specific meta-data will associate
   every uniform name with the period of time during which such a name
   together with its corresponding text is to be considered valid.

   (e.g., the multi-version document containing the "R.D. of 01/30/1941,
   no. 12", updated by the amendments introduced by the "D.Lgs. of
   02/19/1998, no. 51", contains the name of the original
   "state:royal.decree:1941-01-30;12" as well as the name of the updated
   version "state:royal.decree:1941-01-30;12@1998-02-19").

   Please note that in case of attachments or annexes, the creation of a
   new version (even in the case of only one component) would imply the
   creation of a new uniform name for all the connected objects in order
   to guarantee their alignment (i.e., the main document, the
   attachments and annexes).

   As specified in Section 3.6, all the dates can have, in addition to
   the ISO format, also the date typical of the jurisdiction.

8.  Summary of the Syntax of the Uniform Names of the "lex" Namespace

   ;-------------------------------------------------------------------
   ; Structure of a Uniform Resource Name (URN) of the "lex" namespace
   ; - NID-lex = namespace
   ; - NSS-lex = specific name
   ;-------------------------------------------------------------------

   URN-lex = "urn:" NID-lex ":" NSS-lex

   NID-lex = "lex"

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   ;-------------------------------------------------------------------
   ; Structure of a "lex" specific name
   ;-------------------------------------------------------------------

   NSS-lex = jurisdiction ":" local-name

   ;-------------------------------------------------------------------
   ; Structure of the jurisdiction element
   ;-------------------------------------------------------------------

   jurisdiction = jurisdiction-code *(";" jurisdiction-unit)

   jurisdiction-code = 2*alf-dot

   jurisdiction-unit = alf-dot

   ;-------------------------------------------------------------------
   ; Structure of the local-name element
   ;-------------------------------------------------------------------

   local-name = work ["@" expression] ["$" manifestation]

   ;-------------------------------------------------------------------
   ; Structure of the work element
   ;-------------------------------------------------------------------

   work = authority ":" measure ":" details *(":" annex)

   ;-------------------------------------------------------------------
   ; Structure of the authority element
   ;-------------------------------------------------------------------

   authority = issuer *("+" issuer)

   issuer = (institution *(";" body-function)) / office

   institution = alf-dot

   body-function = alf-dot

   office = alf-dot

   ;-------------------------------------------------------------------
   ; Structure of the measure element
   ;-------------------------------------------------------------------

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   measure = measure-type *(";" specification)

   measure-type = alf-dot

   specification = alf-dot

   ;-------------------------------------------------------------------
   ; Structure of the details element
   ;-------------------------------------------------------------------

   details = (dates / period) ";" numbers

   dates = date *("," date)

   period = alf-dot

   numbers = (document-id *("," document-id)) / number-lex

   document-id = alf-dot-oth

   number-lex = "lex-" 1*DIGIT

   ;-------------------------------------------------------------------
   ; Structure of the annex element
   ;-------------------------------------------------------------------

   annex = annex-id *(";" specification)

   annex-id = alf-dot

   ;-------------------------------------------------------------------
   ; Structure of the expression element
   ;-------------------------------------------------------------------

   expression = version [":" language]

   ;-------------------------------------------------------------------
   ; Structure of the version element
   ;-------------------------------------------------------------------

   version = (amendment-date / specification)
          *(";" (event-date / event))

   amendment-date = date

   event-date = date

   event = alf-dot

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   ;-------------------------------------------------------------------
   ; Structure of the language element
   ;-------------------------------------------------------------------

   language = 2*3alfa *["-" extlang] / 4*8alfa

   extlang  = 3alfa *2("-" 3alfa)

   ;-------------------------------------------------------------------
   ; Structure of the manifestation element
   ;-------------------------------------------------------------------

   manifestation = format ":" editor
                [":" component [":" feature]]

   format = mime *(";" specification)

   mime = alf-dot-hyp

   editor = publisher *(";" specification)

   publisher = alf-dot-hyp

   component = part *(";" specification)

   part = alf-dot-hyp

   feature = attribute *(";" specification)

   attribute = alf-dot-hyp

   ;-------------------------------------------------------------------
   ; Structure of the date
   ;-------------------------------------------------------------------

   date = date-iso ["|" date-loc]

   date-iso = year "-" month "-" day

   year  = 4DIGIT
   month = 2DIGIT
   day   = 2DIGIT

   date-loc = *(alfadot / other)

   ;-------------------------------------------------------------------
   ; Allowed, reserved and future characters
   ;-------------------------------------------------------------------

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   ; - allowed = alfadot / other / reserved
   ; - reserved = ":" / "@" / "$" / "+" / "|" / ";" / "," / "~"
   ; - future = "*" / "!"

   alf-dot = alfanum *alfadot
   alf-dot-hyp = alfanum *(alfadot / "-")

   alf-dot-oth = alfanum *(alfadot / other)

   alfadot = alfanum / "."

   alfa = lowercase / uppercase

   alfanum = alfa / DIGIT / encoded

   lowercase = %x61-7A        ; lower-case ASCII letters (a-z)

   uppercase = %x41-5A        ; upper-case ASCII letters (A-Z)

   DIGIT     = %x30-39        ; decimal digits (0-9)

   encoded   = "%" 2HEXDIG

   HEXDIG = DIGIT / %x41-46 / %x61-66 ; hex digits (0-9,A-F,a-f)

   other    = "-" / "_" / "'" / "=" / "(" / ")"

9.  The Procedure of Uniform Names Assignment

9.1.  Specifying the jurisdiction Element of the LEX Identifier

   Under the "lex" namespace, each country or international organization
   is assigned with a jurisdiction code, which characterizes the URNs of
   the source of law of that country or jurisdiction.  This code is
   assigned according to ccTLD (as well as TLDN (Top Level Domain Name)
   or DN (Domain Name) for the organizations) representation and it is
   the value of the jurisdiction-code element, which preserves cross-
   country uniqueness of the identifiers.

9.2.  Jurisdictional Registrar for Names Assignment

   Any country or jurisdiction, who intends to adopt this schema, MUST
   identify a Jurisdictional Registrar, an organization which shares and
   defines the structure of the optional part (jurisdiction-unit) of the
   name, according to the organization of the state or institution (for
   details see Section 2.2).  It must appoint a Jurisdictional Registrar
   and inform the Designed Experts, together with the registration of a
   jurisdiction code.  For example, in a federal state a jurisdiction-

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   unit corresponding to the name of each member state
   (e.g. "br;sao.paulo", "br;minas.gerais", etc.) may be defined.

   The process of assigning the local-name is managed by each specific
   country or jurisdiction under the related jurisdiction element.

   In any country the Jurisdictional Registrar shares and defines the
   assignment of the primary elements (issuing authority and type of
   legal measure) of the local names considering the characteristics of
   its own state or institution organization.

   Such a Registrar MUST establish, according to the guidelines
   indicated in this document, a uniform procedure within the country or
   organization to define local-name elements, to take decisions upon
   normalizations and finally to solve and avoid possible name
   collisions as well as to maintain authoritative registries of various
   kinds (e.g., for authorities, types of measures, etc.).  In
   particular, accurate point-in-time representations of the structure
   and naming of government entities are important to semantically-aware
   applications in this domain.

   Moreover, the Registrar shares and defines the rules to construct
   partition IDs for each document type, possibly in accordance with
   those already defined in other jurisdictions.

   Finally, the Registrar will develop and publish the rules and the
   guidelines for the local-name construction as well as the predefined
   values and codes.  The Registrar should also promote the urn:lex
   identifier for the sources of law of its jurisdiction.

   Such a set of rules will have to be followed by all institutional
   bodies adopting the URN LEX identification system in a country or
   jurisdiction, as well as by private publishers, and each of them will
   be responsible for assigning names to their domains.

9.3.  Identifier Uniqueness

   Identifiers in the "lex" namespace are defined through a jurisdiction
   element assigned to the sources of law of a specific country or
   organization, and a local-name assigned by the issuing authority, in
   conformance with the syntax defined in Section 5.  The main elements
   (authority and type of measure) of the local-name are defined by the
   Jurisdictional Registrar, so that it is ensured that the constructed
   URNs are unique.  The Jurisdictional Registrar MUST provide clear
   documentation of rules by which names are to be constructed, and MUST
   update and make accessible its registries.

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   Any enacting authority is responsible to define formal parameters to
   guarantee local name uniqueness by attributing, if necessary, a
   conventional internal number, which, combined with the other local-
   name components (authority, measure and date), builds a unique
   identifier.  Uniqueness is achieved by checking against the catalogue
   of previously assigned names.

9.4.  Identifier Persistence Considerations

   The persistence of identifiers depends on the durability of the
   institutions that assign and administer them.  The goal of the LEX
   schema is to maintain uniqueness and persistence of all resources
   identified by the assigned URNs.

   In particular, the CNR, as proposer, is responsible of maintaining
   the uniqueness of the jurisdiction element; given that the
   jurisdiction is assigned on the basis of the long-held ccTLD
   representation of the country (or the TLDN or DN of the organization)
   and that the country or organization associated code is expected to
   continue indefinitely, the URN also persists indefinitely.

   The rules for the construction of the name are conceived to delegate
   the responsibility of their uniqueness to a set of authorities which
   is identified within each country or organization.

   Therefore, each authority is responsible for assigning URNs which
   have a very long life expectancy and can be expected to remain unique
   for the foreseeable future.  Practical and political considerations,
   as well as diverse local forms of government organization, will
   result in different methods of assigning responsibility for different
   levels of the name.

   Where this cannot be accomplished by the implementation of an
   authoritative hierarchy, it is highly desirable that it be done by
   creating consensus around a series of published rules for the
   creation and administration of names by institutions and bodies that
   operate by means of collaboration rather than compulsion.

   Issuing authorities that operate in more localized scopes, ranging
   from the national down to the very local, MUST equally take
   responsibility for the persistence of identifiers within their scope.

10.  Recommendations for the Resolution Process

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10.1.  The General Architecture of the System

   The task of the resolution service is that of associating a LEX
   identifier with a specific document address on the network.  By
   contrast with systems that can be constructed around rigorous and
   enforceable engineering premises, such as DNS, the "lex" namespace
   resolver will be expected to cope with a wide variety of inputs
   incomplete or partially incorrect, particularly those created by the
   automated extraction of references from texts.  In this document, the
   result is a particular emphasis on a flexible and robust resolver
   design.

   The system has a distributed architecture based on two fundamental
   components: a chain of information in DNS (Domain Name System) and a
   series of resolution services from URNs to URLs, each competent
   within a specific domain of the namespace.

   The client retrieves the document associated with this URN using the
   procedure described in [RFC3404], which starts with a DNS NAPTR
   query.

   A resolution service can delegate the resolution and management of
   hierarchically-dependent portions of the name.  Delegation of this
   responsibility will not be unreasonably withheld provided that the
   processes for their resolution and management are robust and are
   followed.

   For the "lex" namespace, CNR will maintain in the lex-nameserver (see
   Section 12) the root zone of the chain resolution (equivalent to
   "lex.urn.arpa", see [RFC3405]) and, in correspondence with the
   adhesion (see Section 2.2) of a new country (e.g., "br") or
   organization, will update the DNS information with a new record to
   delegate the relative resolution.  This may be obtained by a regular
   expression that matches the initial part of the URN (e.g.,
   "urn:lex:br") and redirects towards the proper zone (e.g.,
   "lex.senado.gov.br").

   Likewise the institution responsible for the jurisdiction uniform
   names (e.g., "urn:lex:br") has the task of managing the relative root
   in the DNS system (e.g., "lex.senado.gov.br" zone) and routing the
   resolution towards its resolvers on the basis of parts of the uniform
   names.  In similar way it can delegate the resolution of country/
   organization sub-levels (e.g., "urn:lex:br;sao.paolo") towards the
   relative zone (e.g., "lex.sao-paolo.gov.br").

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   Such DNS routing chain does not work for all the URN components
   containing %-encoded characters.  Therefore, when converting a
   lex:URN in UTF-8 code to a DNS query, clients MUST perform any
   necessary punycode conversion [RFC5891] before sending the query.

   The resolution service is made up of two elements: a knowledge base
   (consisting in a catalogue or a set of transformation rules) and a
   software to query the knowledge base itself.

10.2.  Catalogues for Resolution

   Incompleteness and inaccuracy are rather frequent in legal citations,
   and incomplete or inaccurate uniform names of the referred document
   are thus likely to be built from textual references (this is even
   more frequent if they are created automatically through a specific
   parser).  For this reason, the implementation of a catalogue, based
   on a relational-database, is suggested, as it will lead to a higher
   flexibility in the resolution process.

   In addition the catalogue must manage the aliases, the various
   versions and languages of the same source of law as well as the
   related manifestations.

   It is suggested that each enacting authority implements its own
   catalogue, assigning a corresponding unambiguous uniform name to each
   resource.

10.3.  Suggested Resolver Behaviour

   First, the resolver SHOULD separate the part corresponding to the
   partition ID, through the "~" separator, from the document name.

   The resolution process SHOULD implement a normalization of the
   uniform name to be resolved.  This may involve transforming some
   components to the canonical form (e.g., filling out the acronyms,
   expanding the abbreviations, unifying the institution names,
   standardizing the type of measures, etc.).  For this function
   authorities and types of measure registers are useful.

   The resolver SHOULD then query the catalogue searching for the URN
   which corresponds exactly to the given one (normalized if necessary).
   Since the names coming from the references may be inaccurate or
   incomplete, an iterative, heuristic approach (based on partial
   matches) is indicated.  Incomplete references (not including all the
   elements to create the canonical uniform name) are normal and
   natural; for a human reader, the reference would be "completed" by
   contextual understanding of the reference in the document in which it
   occurs.

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   In this phase, the resolver should use the partition ID information
   to retrieve, if it is possible, only the referred partition,
   otherwise to return the entire document.

   Lacking more specific indications, the resolver SHOULD select the
   best (most recent) version of the requested source of law, and
   provide all the manifestations with their related items.  A more
   specific indication in the uniform name to be resolved will, of
   course, result in a more selective retrieval, based on any suggested
   expression and/or manifestations components (e.g. date, language,
   format, etc.).

   Finally, the resolver SHOULD append to URLs the "#" character
   followed by partition ID, transforming it in a URI fragment for
   browser pointing.

11.  Security Considerations

   Security considerations are those normally associated with the use
   and resolution URNs in general.  Additional security considerations
   concerning the authenticity of a document do not pertain to the LEX
   specifications, but they pertain security and trust issues which can
   be addressed with other means, like digital signature, data
   encryption, etc.

12.  IANA Considerations

   IANA has already registered the "lex" namespace, according to the
   template at section 2.  Registration has been accomplished as the
   Formal URN Namespace registry described by [RFC8141].

   In addition, to activate a distributed resolution system, the one-off
   registration of the following NAPTR records is requested:

   in the URN.ARPA domain:

        IN NAPTR  1    0  ""  ""  "!^urn:lex:!_lex!i"  .
   _lex IN NAPTR  10  10  ""  ""  ""  lex-nameserver.

   in the URN.URI.ARPA domain:

        IN NAPTR  1    0  ""  ""  "!^urn:lex:!_lex!i"  .
   _lex IN NAPTR  10  10  ""  ""  ""  lex-nameserver.

   where lex-nameserver indicates the server of the organization that is
   responsible for the resolution of the "lex" namespace and will be
   communicated by the applicant when the application is approved.

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13.  Acknowledgements

   The authors of this document wish to thank all the supporters for
   giving suggestions and comments.

   They are also grateful to the Legislative XML community [SART] for
   the interesting discussions on this topic and to the Working Group
   "Identification of the legal resources through URNs" of Italian
   NormeInRete project for the provided guidance [SPIN].

   The authors owe a debt of gratitude to Tom Bruce, director of the
   Legal Information Institute of the Cornell University Law School, for
   his contribution in revising this document and sharing fruitful
   discussions which greatly improved the final draft.  The authors wish
   to specially thank Marc van Opijnen (Dutch Ministry of Security and
   Justice) for his valuable comments on LEX specifications which
   contributed to improve the final result, as well as for the common
   work aimed to harmonize ECLI and LEX specifications.  Thanks also to
   Joao Alberto de Oliveira Lima, legislative system analyst of the
   Brazilian Federal Senate, and to Attila Torcsvari, information
   management consultant, for their detailed comments on the first
   drafts of this document, which provided significant hints to the
   final version of the standard, and to Robert Richards of the Legal
   Information Institute (Cornell University Law School), promoter and
   maintainer of the Legal Informatics Research social network, as well
   as to the members of this network, for their valuable comments on
   this proposal.

   Finally, many thanks go to Loriana Serrotti who significantly
   contributed to the first drafting of this document.

14.  References

14.1.  Normative References

   [RFC2045]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part One: Format of Internet Message
              Bodies", RFC 2045, DOI 10.17487/RFC2045, November 1996,
              <https://www.rfc-editor.org/info/rfc2045>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
              10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
              2003, <https://www.rfc-editor.org/info/rfc3629>.

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   [RFC3404]  Mealling, M., "Dynamic Delegation Discovery System (DDDS)
              Part Four: The Uniform Resource Identifiers (URI)",
              RFC 3404, DOI 10.17487/RFC3404, October 2002,
              <https://www.rfc-editor.org/info/rfc3404>.

   [RFC3405]  Mealling, M., "Dynamic Delegation Discovery System (DDDS)
              Part Five: URI.ARPA Assignment Procedures", BCP 65,
              RFC 3405, DOI 10.17487/RFC3405, October 2002,
              <https://www.rfc-editor.org/info/rfc3405>.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              <https://www.rfc-editor.org/info/rfc3986>.

   [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234,
              DOI 10.17487/RFC5234, January 2008,
              <https://www.rfc-editor.org/info/rfc5234>.

   [RFC5646]  Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying
              Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646,
              September 2009, <https://www.rfc-editor.org/info/rfc5646>.

   [RFC5891]  Klensin, J., "Internationalized Domain Names in
              Applications (IDNA): Protocol", RFC 5891,
              DOI 10.17487/RFC5891, August 2010,
              <https://www.rfc-editor.org/info/rfc5891>.

   [RFC5893]  Alvestrand, H., Ed. and C. Karp, "Right-to-Left Scripts
              for Internationalized Domain Names for Applications
              (IDNA)", RFC 5893, DOI 10.17487/RFC5893, August 2010,
              <https://www.rfc-editor.org/info/rfc5893>.

   [RFC5894]  Klensin, J., "Internationalized Domain Names for
              Applications (IDNA): Background, Explanation, and
              Rationale", RFC 5894, DOI 10.17487/RFC5894, August 2010,
              <https://www.rfc-editor.org/info/rfc5894>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [RFC8141]  Saint-Andre, P. and J. Klensin, "Uniform Resource Names
              (URNs)", RFC 8141, DOI 10.17487/RFC8141, April 2017,
              <https://www.rfc-editor.org/info/rfc8141>.

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   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8288]  Nottingham, M., "Web Linking", RFC 8288,
              DOI 10.17487/RFC8288, October 2017,
              <https://www.rfc-editor.org/info/rfc8288>.

   [ISO.8601.1988]
              International Organization for Standardization, "Data
              elements and interchange formats - Information interchange
              - Representation of dates and times", ISO Standard 8601,
              June 1988.

   [W3C.HTML] "HTML", W3C REC html, W3C html,
              <https://www.w3.org/TR/html/>.

14.2.  Informative References

   [FRAN]     Francesconi, E., "Technologies for European Integration.
              Standards-based Interoperability of Legal Information
              Systems", ISBN 978-88-8398-050-3, 2007.

   [FRBR]     "Functional Requirements for Bibliographic Records", n.d.,
              <https://www.ifla.org/files/assets/cataloguing/frbr/
              frbr_2008.pdf>.

   [HCPIL]    The European Commission, "The Hague Conference on Private
              International Law "Access to Foreign Law in Civil and
              Commercial Matters. Conclusions and Recommendations"",
              2012, <https://assets.hcch.net/docs/b093f152-a4b3-4530-
              949e-65c1bfc9cda1.pdf>.

   [ISBD]     The Standing Committee of the IFLA Cataloguing Section 
              Berlin/Munich\: De Gruyter Saur, "International Standard
              Bibliographic Description - Consolidated Edition.",
              ISBN 978-3-11-026379-4, 2011.

   [ISO3166-1]
              International Organization for Standardization, "Codes for
              the representation of names of countries and their
              subdivisions -- Part 1: Country codes".

   [LVI]      Peruginelli, G., Ed. and M. Ragona, Ed., "Law via the
              Internet. Free Access, Quality of Information,
              Effectiveness of Rights", ISBN 9788883980589, 2008.

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   [SART]     Sartor, G., Palmirani, M., Francesconi, E., and M.
              Biasiotti, "Legislative XML for the Semantic Web.
              Principles, Models, Standards for Document Management,
              Law, Governance and Technology Series",
              ISBN 978-94-007-1887-6, 2011.

   [SPIN]     Spinosa, P., "The Assignment of Uniform Names to Italian
              Legal Documents, URN-NIR 1.4", ITTIG technical Report n.
              8/2010., June 2020.

   [W3C.rdf-schema]
              "RDF Schema 1.1", W3C REC rdf-schema, W3C rdf-schema,
              <https://www.w3.org/TR/rdf-schema/>.

Authors' Addresses

   PierLuigi Spinosa
   Via Zanardelli, 15
   50136 Firenze
   Italy
   Phone: +39 339 5614056
   Email: pierluigi.spinosa@gmail.com

   Enrico Franceseconi
   Consiglio Nazionale delle Ricerche (CNR)
   Via de' Barucci, 20
   50127 Firenze
   Italy
   Phone: +39 055 43995
   Email: enrico.francesconi@cnr.it

   Caterina Lupo
   Via San Fabiano, 25
   117 Roma
   Italy
   Phone: +39 3382632348
   Email: caterina.lupo@gmail.com

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