IETF URNbis WG J. Hakala
Internet-Draft The National Library of Finland
Obsoletes: 3188 (if approved) A. Hoenes, Ed.
Intended status: Standards Track TR-Sys
Expires: July 22, 2012 January 19, 2012
Using National Bibliography Numbers as Uniform Resource Names
draft-ietf-urnbis-rfc3188bis-nbn-urn-02
Abstract
National Bibliography Numbers, NBNs, are widely used by the national
libraries and other organizations in order to identify various
resources such as digitized monographs. Generally, NBNs may be
applied to all kinds of resources that do not have an established
(standard) identifier system of their own.
A URN (Uniform Resource Names) namespace for NBNs was established in
2001 in RFC 3188. Since then, several national libraries in several
European countries have implemented URN:NBN-based systems.
This document replaces RFC 3188 and defines how NBNs can be supported
within the updated URN framework. A revised namespace registration
(version 4) is included.
Discussion
Comments are welcome and should be directed to the urn@ietf.org
mailing list or the authors.
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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Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 22, 2012.
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Copyright Notice
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document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions used in this document . . . . . . . . . . . . . . 5
3. Fundamental Namespace and Community Considerations for NBN . . 6
3.1. The URN:NBN Namespace . . . . . . . . . . . . . . . . . . 6
3.2. Community Considerations for NBNs . . . . . . . . . . . . 6
4. National Bibliography Numbers (NBNs) . . . . . . . . . . . . . 8
4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2. Encoding Considerations and Lexical Equivalence . . . . . 9
4.3. Resolution and Persistence of NBN-based URNs . . . . . . . 10
4.4. Additional Considerations . . . . . . . . . . . . . . . . 11
5. URN Namespace ID Registration for the National
Bibliography Number (NBN) . . . . . . . . . . . . . . . . . . 12
6. Security Considerations . . . . . . . . . . . . . . . . . . . 16
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
9.1. Normative References . . . . . . . . . . . . . . . . . . . 17
9.2. Informative References . . . . . . . . . . . . . . . . . . 17
Appendix A. Significant Changes from RFC 3188 . . . . . . . . . . 18
Appendix B. Draft Change Log . . . . . . . . . . . . . . . . . . 19
B.1. draft-hakala-rfc3188bis-nbn-urn-00 to
draft-ietf-urnbis-*-00 . . . . . . . . . . . . . . . . . . 19
B.2. draft-ietf-urnbis-rfc3188bis-nbn-urn-00 to -01 . . . . . . 19
B.3. draft-ietf-urnbis-rfc3188bis-nbn-urn-01 to -02 . . . . . . 19
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1. Introduction
One of the basic permanent URI schemes (cf. RFC 3986 [RFC3986],
[IANA-URI]) is 'URN' (Uniform Resource Name) as originally defined in
RFC 2141 [RFC2141] and now being formally specified in RFC 2141bis
[I-D.ietf-urnbis-rfc2141bis-urn]. Any traditional identifier, when
used within the URN system, needs to have a namespace of its own. As
of December 2011, IANA had registered 45 formal URN namespaces (see
[IANA-URN]), one of which belongs to NBN, National Bibliography
Number, as specified 2001 in RFC 3188 [RFC3188].
URN:NBNs are in production use in several European countries
including (in alphabetical order) Austria, Finland, Germany, Italy,
the Netherlands, Norway, Sweden, and Switzerland; several other
countries in Europe and elsewhere are considering usage of them. The
URN:NBN namespace is managed by the national libraries. URN:NBNs
have been applied to diverse content including Web archives,
digitized materials, research data, and doctoral dissertations. They
can be used by the national libraries and organizations co-operating
with them.
As a part of the initial development of the URN system back in the
late 1990s, the IETF URN working group agreed that it was important
to demonstrate that the URN syntax can accommodate existing
identifier systems.
RFC 2288 [RFC2288] investigated the feasibility of using three
identifiers (ISBN, ISSN and SICI, see below) as URNs, with positive
results; however, it did not register corresponding URN namespaces.
This was in part due to the still evolving process to formalize
criteria for namespace definition documents and registration,
consolidated later in the IETF into RFC 3406 [RFC3406]. That RFC, in
turn, is now being updated as well into RFC 3406bis
[I-D.ietf-urnbis-rfc3406bis-urn-ns-reg].
URN Namespaces have subsequently been registered for NBN (National
Bibliography Number), ISBN (International Standard Book Number), and
ISSN (International Serial Standard Number) in RFCs 3188 [RFC3188],
3187 [RFC3187], and 3044 [RFC3044], respectively. The ISBN namespace
registration is being revised so that it will cover both ISBN-10 and
ISBN-13; [I-D.ietf-urnbis-rfc3187bis-isbn-urn]. The current ISSN
registration still does not cover ISSN-L, defined in the new version
of the ISSN standard; there also is work in progress in the URNbis WG
to update the existing namespace registration, RFC 3044 [RFC3044].
SICI-based URNs have not been specified to date, mainly due to the
identifier system's limited popularity.
The term "National Bibliography Number" encompasses persistent local
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identifier systems that the national libraries and their partner
organizations use in addition to the more formally (and
internationally) established identifiers. In practice, NBN differs
from the standard identifier systems listed above because it is not a
single identifier system with standard-specified scope and syntax.
Each NBN implementer is obliged to keep track of how NBNs are being
used, but within the generic framework set in this document, local
NBN assignment policies may vary a lot.
Historically, NBNs were only applied in the national bibliographies
to identify the resources catalogued into it. Prior to the emergence
of bibliographic standard identifiers, every publication got an NBN;
after, e.g., the ISBN system was established, NBNs were given only to
those books that did not have an ISBN -- whether due to human error
or because they did not qualify.
During the last 10 years, the NBN scope has been extended to cover a
vast range of digital resources available via the Internet. Only a
small subset of these resources is catalogued in the national
bibliographies or other bibliographic databases. Web contents
harvested into Web archives are an example of resources that will not
be catalogued but may nevertheless receive an NBN.
The NBN scope may be expanded further if necessary. For instance,
NBNs may be used to identify (immaterial) works or data elements, in
order to facilitate linked data. If the identified resource itself
cannot be retrieved via resolution, URN resolution should supply a
surrogate, such as descriptive metadata of the work itself, or
description of the metadata element.
Simple guidelines for using NBNs as URNs and the original namespace
registration were published in RFC 3188 [RFC3188]. The RFC at hand
replaces RFC 3188; sections discussing the methods in which URN:NBNs
should be resolved have been updated, unused features have been
eliminated, and the text is compliant with the stipulations of RFC
3406bis [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg], the successor of
RFC 3406 [RFC3406], which previously had replaced RFC 2611 [RFC2611]
(the latter was applied in the initial registration).
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
NBN refers to any National Bibliography Number identifier system used
by the national libraries and other institutions using the system
with the national library's permission.
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3. Fundamental Namespace and Community Considerations for NBN
3.1. The URN:NBN Namespace
NBNs are widely used to identify hand-held or digital resources
covered by legal requirements on national libraries and similar
institutions to preserve the cultural heritage of their constituents.
All objects in deposit collections will be preserved for long term.
While the methods for digital preservation may vary, the favourite
one is migration. The old versions will not be removed, in order to
alleviate the effects of failed migrations. Eventually there will be
multiple manifestations of most digital resources. Each
manifestation SHOULD have its own NBN. All manifestations of a
resource SHOULD be interlinked, for example via providing persistent
links in the descriptive metadata.
NBNs SHOULD only be used for objects when the standard identifiers
such as ISBN are not applicable. However, they MAY be used for
component parts (fragments) even when the identified resources as a
whole qualify for standard identifiers. For instance, even if an
e-book has an ISBN, an image within the book MAY receive an NBN if
the image is available separately.
The scope of standard identifier systems such as ISBN and ISSN is
limited; they are applicable only to certain kinds of resources. The
role of the NBN is to fill in the gaps. Collectively, the standard
bibliographic identifiers and NBNs cover -- at least in theory -- all
resources the national libraries and their partners need to preserve
for long term.
Section 4 below, and there in particular Section 4.1, presents a more
detailed overview of the structure of the NBN namespace, related
institutions, and the identifier assignment principles used.
3.2. Community Considerations for NBNs
National libraries are the key organizations providing persistent URN
resolution services for objects identified with NBNs, independent of
their form. National libraries MAY allow other organizations such as
university libraries or governmental organizations to assign NBNs to
the resources they preserve for long term. In such case, the
national library MUST co-ordinate the use of NBNs at the national
level. The national library MAY also provide URN resolution services
and other technical services to other NBN users. These other
organizations MUST either establish their own resolution services or
use the technical infrastructure provided by the national library.
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NBNs may be used to identify fragments, but the NBN namespace does
not specify a generic, intrinsic syntax for fragment identification.
Any character that could be used to indicate a fragment such as colon
or full stop may already be reserved. However, there are at least
three different ways in which component parts can be identified and
used within the NBN namespace.
The simplest approach is to assign a separate NBN for each component
part. In these cases, the resolution process SHOULD link the URN:NBN
to a URI belonging to an object such as a text file containing a
chapter of a book.
Second, a local fragment syntax MAY be used, independently of the
requirements of RFC 3986. Fragment identifiers will only be
recognized as such in the application responding to the request. It
MUST be able to process the URN:NBN correctly; the result MUST be the
identified logical component of the entire resource, or a surrogate
such as descriptive metadata about the component.
Finally, if the stipulations of the URI standard (RFC 3986
[RFC3986]), the URI Syntax (RFC 2141bis
[I-D.ietf-urnbis-rfc2141bis-urn]), and those of the Internet media
type as specified in RFC 2046 [RFC2046] are met, URI fragment
identifiers MAY be applied in the NBN string. In such cases the
resolution process SHALL retrieve the entire document, and the
fragment selection is then applied to it. This will take the user
to, e.g., the beginning of a relevant journal article within an XML
file containing the entire issue.
Resources identified by NBNs do not need to be available in the
Internet. When the resource itself is not accessible, the URN:NBN
resolver SHOULD supply metadata about the resource, possibly
including information about where its physical manifestations are
stored in the owning institutions' holdings. A resolver MAY also
deliver a digital surrogate, if one exists, or information about
other versions of the object.
If an NBN identifies an immaterial object such as work, descriptive
metadata SHOULD be supplied. These work level metadata records MAY
include links to the physical manifestations of the work. Metadata
records describing these manifestations should include links to each
other and to the work level metadata record. If an NBN identifies a
data element, description of the element SHOULD be supplied.
Section 4 below, and in particular Section 4.3 therein, presents a
detailed overview of the application of the URN:NBN namespace as well
as the principles of, and systems used for, the resolution of NBN-
based URNs.
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4. National Bibliography Numbers (NBNs)
4.1. Overview
National Bibliography Number (NBN) is a generic term referring to a
group of identifier systems administered by the national libraries
and institutions authorized by them. The NBN assignment is typically
performed by the organization hosting the resource. These
organizations (national libraries and institutions in liaison with
them) are usually committed to preserving their deposit collections
for a long time -- at least decades, and possibly centuries.
Resources belonging to these collections SHOULD receive NBNs only if
no standard identifier is applicable.
Each national library uses its own NBNs independently of other
national libraries; there is no global authority that controls NBN
usage. For this reason, NBNs as such are unique only on the national
level. When used as URNs, NBN strings MUST be augmented with a
controlled prefix, which is the particular nation's ISO 3166-1
alpha-2 two-letter country code. These prefixes guarantee uniqueness
of the NBN-based URNs at the global scale [Iso3166MA].
In principle, NBNs enable identification of any kind of resource and
its component parts, such as a periodical and articles published in
it. A national library using URN;NBNs should specify a national
assignment policy; such policy may limit the NBN usage to resources
stored permanently in the national library's legal deposit
collection. But the scope of the NBN assignment can be significantly
broader; for instance, NBNs are already used to identify research
datasets (which are not part of legal deposit in any country yet).
URN:NBN assignment may be automated. Some national libraries (e.g.,
Finland, Norway, Sweden) have established Web-based URN generators,
which enable authors and publishers to retrieve NBN-based URNs.
There are also applications, used for instance in digitization
processes, that generate NBNs automatically for the processed
resources.
Each national library administering a URN:NBN sub-namespace SHOULD
specify a local NBN assignment policy. Such document SHOULD clarify
e.g. the local policy concerning fragment identification and the
local fragment syntax used (if any). The policy MAY also clarify if
works or data elements are included. The policy MAY also specify the
maximum length of the NSS and other relevant syntactical features in
order to simplify NSS parsing.
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4.2. Encoding Considerations and Lexical Equivalence
Expressing NBNs as URNs is usually straightforward, as traditionally
only ASCII characters have been used in NBN strings. If necessary,
NBNs must be translated into canonical form as specified in
RFC 2141bis [I-D.ietf-urnbis-rfc2141bis-urn].
When an NBN is used as a URN, the namespace-specific string (NSS)
MUST consist of three parts:
o a primary prefix, which is a two-letter ISO 3166-1 country code,
o zero or more secondary prefixes, each indicated by a delimiting
colon character (:) and a sub-namespace identifier,
o a hyphen (-) as a delimiting character, and
o the NBN string.
The prefix is case-insensitive. The NBN string MAY be case
sensitive, depending on the NBN syntax applied locally. Future NBN
implementations SHOULD make the NBN string case insensitive as well.
Different delimiting characters are not semantically equivalent.
Use of colon as the delimiting character is allowed if and only if
the country code-based NBN namespace (identified by the respective
ISO 3166-1 country code used as the primary part of the prefix) is
split further into smaller sub-namespaces, in which case the colon
separates the ISO 3166-1 country code from the sub-namespace
identifier. These sub-divisions (including the colon separator) form
an optional part of the prefix. A colon MUST NOT be used for any
other purpose in the prefix.
A hyphen MUST be used for separating the prefix and the NBN string,
or the part of the NBN string that is assigned to the identified
object by a sub-division authority.
If there are several national libraries in one country, these
libraries MUST agree on how to divide the national namespace between
themselves using this method before the URN:NBN assignment begins in
any of these libraries.
A national library MAY also assign to trusted organization(s) such as
a university or a government institution its own NBN sub-namespace.
The sub-namespace MAY be further divided by the partner organization
(or by the national library on request of the partner).
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Being part of the prefix, sub-namespace identifier strings are case-
insensitive. They MUST NOT contain any hyphens.
The sub-namespace identifiers used beneath a country-code-based
namespace MUST be registered on the national level by the national
library that assigned the code. The national register of these codes
SHOULD be made available online.
Models (indicated linebreak inserted for readability):
URN:NBN:<ISO 3166 alpha-2 country code>-<assigned NBN string>
URN:NBN:<ISO 3166 alpha-2 country code>:<sub-namespace code>-\
<assigned NBN string>
Examples (using actually assigned NBNs):
URN:NBN:fi-fe201003181510
urn:nbn:ch:bel-9039
urn:nbn:se:uu:diva-3475
urn:nbn:hu-3006
4.3. Resolution and Persistence of NBN-based URNs
Eventually, URN:NBNs will be resolved with the help of a resolver
discovery service (RDS). No such system has been installed yet in
the Internet infrastructure. Therefore, URN:NBNs MAY be embedded in
HTTP URIs in order to make them actionable in the present Internet.
In these HTTP URIs, the authority part must point to the appropriate
URN resolution service. For instance, in Finland, the address of the
national URN resolver is <http://urn.fi>. Thus the HTTP URI for the
Finnish URN in the example above is
<http://urn.fi/URN:NBN:fi-fe201003181510>. This public persistent
identifier will not change. In contrast, since the resource has
already moved once from one DSpace system to another, its DSpace-
internal Handle has changed (to
https://helda.helsinki.fi/handle/10138/18199). Since Handles are in
this case only internal identifiers, they do not need to persist, and
users are asked to rely on the URN-based HTTP URI when they make
persistent links to the document.
The country code-based prefix part of the URN namespace-specific
string will provide a hint needed to find the correct national
resolution service for URN:NBNs from the resolver discovery service
when it is established.
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There are three inter-related aspects of persistence that need to be
discussed: persistence of the objects itself, persistence of the
identifier and persistence of the URN resolvers.
NBNs have traditionally been assigned to printed resources, which
tend to be persistent. Many books published in the 15th century are
still perfectly readable. In contrast, digital resources require
frequent migrations to guarantee accessibility. Although it is
impossible to estimate how often migrations are needed, hardware and
software upgrades take place frequently, and even a life time of
10-20 years can be considered as long.
Migration is often a lossy process, so different manifestations of an
object may have different look and feel, and possibly even
intellectual content. Because of this, each manifestation must have
a different identifier. Any intellectual work will eventually be
represented by a set of manifestations in which each successive
version is likely to be more and more distant from the original
object. It is not possible to know which one of these versions will
fit the needs of a user best; therefore it is necessary to interlink
URNs belonging to the different manifestations of an object (possibly
via a work level metadata record) so as to make the users aware of
all the existing manifestations of the object and to enable them to
retrieve the one that matches their interests best.
Thus, even if manifestations of digital objects are not and will not
be persistent per se, persistent identifiers such as URN:NBNs SHOULD
support construction of an information architecture thath enables
persistent access to the identified intellectual content, although
the look and feel of their manifestations will inevitably change over
time.
Persistence of URN resolvers themselves is mainly an organizational
issue, related to the persistence of organizations maintaining them.
As URN:NBN resolution services will be supplied (primarily) by the
national libraries to enable access to their (legal) deposit
collections, these services SHOULD be persistent.
4.4. Additional Considerations
URN:NBNs should not be assigned to resources that will not be
preserved for long term. If there are multiple copies of the
resource in the Internet, the resolutuion process SHOULD include all
of them. If this is not possible, a URN:NBN should resolve to the
copy that is deemed to be the most persistent one.
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5. URN Namespace ID Registration for the National Bibliography Number
(NBN)
This registration describes how National Bibliography Numbers (NBNs)
can be supported within the URN framework.
[[ RFC Editor: please replace "XXXX" in all instances of "RFC XXXX"
below by the RFC number assigned to this document. ]]
Namespace ID: NBN
This Namespace ID was formally assigned to the National
Bibliography Number in October 2001 when the namespace was
registered officially. Utilization of URN:NBNs had started in
demo systems already in 1998. Since 2001, tens of millions of
URN:NBNs have been assigned. The number of users of the namespace
has grown in two ways: new national libraries have started using
NBNs, and some national libraries using the system have formed new
liaisons.
Registration Information:
Version: 4
Date: 2012-01-19
Declared registrant of the namespace:
Name: Mr. Juha Hakala
Affiliation: Senior Adviser, The National Library of Finland
Email: juha.hakala@helsinki.fi
Postal: P.O.Box 15, 00014 Helsinki University, Finland
Web URL: http://www.nationallibrary.fi/
The National Library of Finland registered the namespace on behalf
of the Conference of the European National Librarians (CENL) and
Conference of Directors of National Libraries (CDNL), which have
both made a commitment in 1998 to foster the use of URNs. The NBN
namespace is available for free for the national libraries and the
organizations co-operating with them. The national libraries may
allow these organizations to use the namespace for free or for a
fee; such fees, if collected, may be based on, e.g., the
maintenance costs of the system.
Declaration of syntactic structure of NSS part:
The namespace-specific string (NSS) will consist of three parts:
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a prefix, consisting of an ISO 3166-1 alpha-2 country code and
optional sub-namespace code(s) separated by colon(s),
a hyphen (-) as the delimiting character, and
an NBN string assigned by the national library or sub-delegated
authority.
Formal declaration of the NSS, using ABNF [RFC5234]:
nbn_nss = prefix "-" nbn_string
prefix = iso_cc *( ":" subspc )
; the entire prefix is case-insensitive
iso_cc = 2ALPHA
; country code as assigned by ISO 3166, part 1 --
; identifies the national library
; to which the branch is delegated
subspc = 1*(ALPHA / DIGIT)
; as assigned by the respective national library
nbn_string = <specific per prefix>
; MUST adhere to RFC 3986 <path-rootless> syntax;
; parsers must regard nbn_strings as case-sensitive
Colon MAY be used as a delimiting character only within the
prefix, between ISO 3166-1 country code and sub-namespace code(s),
which split the national namespace into smaller parts.
Whereas the prefix is regarded as case-insensitive, NBN-strings
MAY be case-sensitive at the preference of the assigning
authority; parsers therefore MUST treat these as case-sensitive;
any case mapping needed to introduce case-insensitivity MUST be
implemented in the responsible resolution system.
Hyphen MUST be used as the delimiting character between the prefix
and the NBN string. Within the NBN string, hyphen MAY be used for
separating different sections of the identifier from one another.
All two-letter codes are reserved by the ISO 3166 Maintenance
Agency for either existing and possible future ISO country codes
(or for private use).
Sub-namespace identifiers MUST be registered on the national level
by the national library that assigned the code. The list of such
identifiers SHOULD be available via the Web.
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See Section 4.2 of RFC XXXX for examples.
Relevant ancillary documentation:
National Bibliography Number (NBN) is a generic name referring to
a group of identifier systems used by the national libraries and
other organizations for identification of deposited publications
and other resources (and their component parts) that lack a
'canonical' identifier. NBN can also be used to identify, e.g.,
intellectual works and data elements. Each national library uses
its own NBN system independently of other national libraries;
there is neither a general standard defining the NBN syntax nor a
global authority to control the use of these identifier systems.
The syntax of NBN strings is specified by each national library
independently. Historically, NBNs used in national bibliographies
contained only characters that belong to the US-ASCII character
set. Following the expansion of NBN scope and semi- and fully
automated NBN assignment processes, some NBNs may contain
characters that must be translated into canonical form according
to the specifications in RFC 2141bis
[I-D.ietf-urnbis-rfc2141bis-urn].
Conformance with URN syntax:
The NSS syntax specified in this registration is in full
conformance with RFC 2141bis [I-D.ietf-urnbis-rfc2141bis-urn] and
its predecessor.
Rules for lexical equivalence of NSS part:
Prefix, consisting of either ISO 3166-1 country code and its
(optional) sub-divisions, is case-insensitive. NBN string MAY be
case-sensitive; the recommendation is that new NBN implementations
should be case-insensitive. Requirements expressed in RFC 2141bis
[I-D.ietf-urnbis-rfc2141bis-urn] must be taken into account as
well.
Formally, two URN:NBNs are lexically equivalent if they are octet-
by-octet equal after the following (conceptional) preprocessing:
1. normalize the case of the leading "urn:" token;
2. normalize the case of the prefix (country code and its optional
sub-divisions);
3. normalize the case of any percent-encoding;
Note: The case used in the normalization steps is a local matter;
implementations can normalize to lower or upper case as they see
fit, they only need to do it consistently.
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Identifier uniqueness and persistence considerations:
It is possible that two national libraries assign the same NBN to
different documents. In such case, the prefix guarantees the
uniqueness of the NBN-based URNs. URN:NBNs, once given to the
resource, MUST be persistent. Persistence of the resources
themselves will be guaranteed by the national libraries as a part
of their legal deposit activities.
An NBN, once it has been assigned, MUST never be re-used for
another resource.
Users of the NBN namespace MUST make sure that they do not assign
the same NBN twice. They can utilise different policies for this.
The identifiers can be assigned sequentially by programs (URN
generators) in order to avoid human mistakes. It is also possible
to use printable representations of checksums such as SHA-1
[RFC6234] or MD5 [RFC1321] as NBN, as long as the registration
process prevents collisions (irrespective of the minuscule
probability for these to occur).
Process of identifier assignment:
Assignment of NBN-based URNs MUST be controlled on national level
by the national library / national libraries. Although the basic
principles are the same, there MAY be differences in scope. The
common denominator, however, is that the identified resources
themselves are persistent.
National libraries have applied different policies in assigning
NBN-based URNs, and different approaches have varying levels of
control with respect to the persistence of the documents. Manual
URN assignment by the library personnel provides the best possible
control, especially if this is done only when the document is
catalogued into the national bibliography. In most libraries, the
scope of URN:NBN is much broader than this. From a control point
of view, the most liberal approach is a URN generator that builds
URNs for anonymous users, with no guarantee that the resource
identified will be preserved or accessible. Every national
library must decide the degree of freedom it allows to the URN:NBN
assignment. Usage rules may of course vary within one country,
from one sub-namespace to the next. As of yet there are no
international guidelines for NBN use beyond what has been
stipulated above, but more stringent rules may be developed in the
future.
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Process for identifier resolution:
See Section 4.3 of RFC XXXX.
Validation mechanism:
None specified on the global level (beyond a routine check of
those characters that require special encoding when employed in
URIs). NBNs may have a well specified and rich syntax (including,
e.g., fixed length and checksum). In such case, it is possible to
validate the correctness of the NBN programmatically.
Scope:
NBN are applied to resources held in the collections of national
libraries and their partner organizations. NBNs may also be used
to identify, e.g., works that these resources manifest, and the
data elements present in the resource metadata.
6. Security Considerations
This document proposes means of encoding NBNs within the URN
framework. A URN resolution service for NBN-based URNs is depicted,
but only at a generic level; thus, questions of secure or
authenticated resolution mechanisms and authentication of users are
out of scope of this document. It does not deal with means of
validating the integrity or authenticating the source or provenance
of URNs that contain NBNs. Issues regarding intellectual property
rights associated with objects identified by the NBNs are also beyond
the scope of this document, as are questions about rights to the
databases that might be used to construct resolution services.
7. IANA Considerations
IANA is asked to update the existing registration of the Formal URN
Namespace 'NBN' using the template given above in Section 5.
8. Acknowledgements
Revision of RFC 3188 started during the project PersID
(<http://www.persid.org>). Later the revision was included in the
charter of the URNbis working group in the Applications Area. The
author wishes to thank his colleagues in the PersID project and the
URNbis participants for their support.
Tommi Jauhiainen has provided feedback on an early version of this
draft.
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9. References
9.1. Normative References
[I-D.ietf-urnbis-rfc2141bis-urn]
Hoenes, A., "Uniform Resource Name (URN) Syntax",
draft-ietf-urnbis-rfc2141bis-urn-01 (work in progress),
October 2011.
[I-D.ietf-urnbis-rfc3406bis-urn-ns-reg]
Hoenes, A., "Uniform Resource Name (URN) Namespace
Definition Mechanisms",
draft-ietf-urnbis-rfc3406bis-urn-ns-reg-01 (work in
progress), October 2011.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008.
9.2. Informative References
[I-D.ietf-urnbis-rfc3187bis-isbn-urn]
Huttunen, M., Hakala, J., and A. Hoenes, "Using
International Standard Book Numbers as Uniform Resource
Names", draft-ietf-urnbis-rfc3187bis-isbn-urn-01 (work in
progress), October 2011.
[IANA-URI]
IANA, "URI Schemes Registry",
<http://www.iana.org/assignments/uri-schemes>.
[IANA-URN]
IANA, "URN Namespace Registry",
<http://www.iana.org/assignments/urn-namespaces>.
[Iso3166MA]
ISO, "ISO Maintenance agency for ISO 3166 country codes",
<http://www.iso.org/iso/country_codes.htm>.
[RFC1321] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321,
April 1992.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046,
November 1996.
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Internet-Draft NBN URN Namespace January 2012
[RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997.
[RFC2288] Lynch, C., Preston, C., and R. Jr, "Using Existing
Bibliographic Identifiers as Uniform Resource Names",
RFC 2288, February 1998.
[RFC2611] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom,
"URN Namespace Definition Mechanisms", BCP 33, RFC 2611,
June 1999.
[RFC3044] Rozenfeld, S., "Using The ISSN (International Serial
Standard Number) as URN (Uniform Resource Names) within an
ISSN-URN Namespace", RFC 3044, January 2001.
[RFC3187] Hakala, J. and H. Walravens, "Using International Standard
Book Numbers as Uniform Resource Names", RFC 3187,
October 2001.
[RFC3188] Hakala, J., "Using National Bibliography Numbers as
Uniform Resource Names", RFC 3188, October 2001.
[RFC3406] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom,
"Uniform Resource Names (URN) Namespace Definition
Mechanisms", BCP 66, RFC 3406, October 2002.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005.
[RFC6234] Eastlake, D. and T. Hansen, "US Secure Hash Algorithms
(SHA and SHA-based HMAC and HKDF)", RFC 6234, May 2011.
Appendix A. Significant Changes from RFC 3188
Numerous clarifications based on a decade of experience with RFC
3188.
Non-ISO 3166 country code based NBNs have been removed due to lack of
usage.
In accordance with established practice, the whole NBN prefix is now
declared case-insensitive.
Updated URN:NBN Namespace Registration template for IANA; whole
document adapted to new URN Syntax document, RFC 2141bis, and new URN
Namespace Registration document, RFC 3406bis.
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Appendix B. Draft Change Log
[[ RFC-Editor: Whole section to be deleted before RFC publication. ]]
B.1. draft-hakala-rfc3188bis-nbn-urn-00 to draft-ietf-urnbis-*-00
- formal updates for a WG draft; no more "Updates: 2288";
- introduced references to other URNbis WG documents;
- changes based on review by Tommi Jauhiainen;
- Sect. 3 restructured into namespace and community considerations;
- old Sect. 7 incorporated in new Sect. 3.1;
- Security Considerations: old Section 4.5 merged into Section 5;
- added guidelines for when two manifestations of the same work
should get different URN:NBNs;
- clarified role of ISO 3166/MA for ISO 3166-1 country codes;
- clarified role of non-ISO prefix registry maintaind by the LoC;
- resolved inconsistency in lexical equivalence rules: as already
specified for ISO alpha-2 country-codes, and in accordance with
established practice, the whole NBN prefix is now declared case-
insensitive;
- registration template adapted to rfc3406bis [-00];
- numerous editorial fixes and enhancements.
B.2. draft-ietf-urnbis-rfc3188bis-nbn-urn-00 to -01
- Numerous changes to accommodate the outcome of the discussions on
the urn list;
- three different ways of identifying fragments specified;
- removed some redundant/irrelevant paragraphs/subsections;
- the "one manifestation, one URN" principle strenghtened;
- introduced the idea of interlinking manifestations;
- extended the scope of the NBN explicitly to works;
- added reference to S4.2 in namespace registration;
- numerous editorial fixes and enhancements.
B.3. draft-ietf-urnbis-rfc3188bis-nbn-urn-01 to -02
- Removed the possibility of using prefixes not based on country
codes;
- replaced all instances of the word object with resources;
- removed some redundant/irrelevant paragraphs/subsections;
- allowed the possibility for identifying data elements with NBNs;
- a few editorial fixes and enhancements.
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Authors' Addresses
Juha Hakala
The National Library of Finland
P.O. Box 15
Helsinki, Helsinki University FIN-00014
Finland
Email: juha.hakala@helsinki.fi
Alfred Hoenes (editor)
TR-Sys
Gerlinger Str. 12
Ditzingen D-71254
Germany
Email: ah@TR-Sys.de
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