Network Working Group D. Cridland
Internet-Draft Isode Limited
Intended status: Standards Track Aug 17, 2010
Expires: February 18, 2011
The Internet Assigned Number Authority (IANA) Application Configurations
Access Protocol (ACAP) Vendor Subtrees Registry
draft-cridland-acap-vendor-registry-01
Abstract
The original ACAP specification included a vendor registry now used
in other protocols. This document updates the description of this
registry, removing the need for a direct normative reference to ACAP,
and removing ambiguity.
Status of this Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on February 18, 2011.
Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Conventions used in this document . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. The Vendor Subtree Registry . . . . . . . . . . . . . . . . . . 3
3.1. Internationalization . . . . . . . . . . . . . . . . . . . 3
3.2. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . 4
3.3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.4. Changes from RFC 2244 . . . . . . . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Example Registration . . . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . . 6
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 7
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1. 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 [KEYWORDS].
Formal Syntax are to be considered normative, and are specified using
[ABNF]. Where a formal syntax and the prose are in conflict, the
formal syntax takes precedence.
2. Introduction
The [ACAP] specification includes the specification and creation of
the ACAP Vendor Registry, and this registry has subsequently been
reused by several specifications, including both [ANNOTATE] and
[METADATA], and is proving to be a useful mechanism for namespacing
various names to within a specific vendor's scope.
This document merely updates the registry to reduce ambiguity in the
original specification, and dissociates it from the original document
in all but name, allowing easier referencing. It replaces section
7.4 and portions of section 4, particularly 4.3, of [ACAP].
3. The Vendor Subtree Registry
A Vendor Token is a UTF-8 string beginning with "vendor.", and
followed by the name of the company or product. This name MUST NOT
contain any slash character, period, or the percent and asterisk
characters typically used as wildcards.
Following this may be names, separated from the Vendor Token by a
period, which need not be registered, thus forming a complete Vendor
Name.
3.1. Internationalization
Vendor Tokens are able to contain any valid Unicode codepoint,
encoded as [UTF-8], except the special characters. Since the
publication of [ACAP], however, concerns have been raised on the
handling and comparison of full Unicode strings, and therefore this
specification restricts the current registrations to the ASCII subset
of UTF-8.
Furthermore, characters such as control characters, whitespace, and
quotes are likely to be confusing and have been similarly restricted.
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Therefore, this document allows only ASCII letters, digits, the
hyphen, and space to be used.
3.2. Formal Syntax
This syntax draws upon productions found within [ABNF] and [UTF-8].
Productions replace those in section 4.3 of [ACAP].
vendor-name = vendor-token ["." name-component]
name-component = *(name-char / UTF8-2 / UTF8-3 / UTF8-4)
name-char = %x01-24 / %x26-29 / %x2B-2D / %x30-7F
;; ASCII-range characters not including ".",
;; "/", "%", or "*".
vendor-token = "vendor." vendor-tag
vendor-tag = iana-vendor-tag / possible-vendor-tag
iana-vendor-tag = 1*(ALPHA / DIGIT / SP / "-")
;; This production represents
;; allowed forms for current registrations.
possible-vendor-tag = name-component
;; This production represents what
;; applications and specifications
;; may encounter.
3.3. Examples
A company Example Ltd might register the Subtree "vendor.example".
This means it may use "vendor.example", or any name at all beginning
"vendor.example.", such as "vendor.example.product".
These names might be used in several protocols, and are reserved in
all the relevant protocols, so "vendor.example" might be an ACAP
dataset class name, and "/vendor/vendor.example" might be a tree of
IMAP ANNOTATE entries.
Example Ltd is free to use either "vendor.example", and group
specific products under it using the relevant protocol's hierarchy -
perhaps "/shared/vendor/vendor.example/product", or using more
specific names, such as "/shared/vendor/vendor.example.product".
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3.4. Changes from RFC 2244
This non-normative section details changes from RFC 2244's original
specification of the registry.
o UTF-8 names are restricted to ASCII
o Clarifications that "vendor.<company/product name>" means
"vendor.company name" or "vendor.product name" - "vendor.company/
product" is and always has been illegal.
o Made "vendor.company" a name in its own right - RFC 2244 only
refers to a prefix of "vendor.company.".
o Added example registration, in line with [EXAMPLES].
4. IANA Considerations
This specification updates the IANA registry named the ACAP Vendor
Subtrees Registry.
Vendors may reserve a portion of the ACAP namespace, which is also
used as the namespace for several other protocols, for private use.
Vendor Names are reserved for use by that company or product,
wherever used, once registered. Registration is on a first come,
first served basis. Whenever possible, private attributes and
classes should be eschewed in favour of improving interoperable
protocols.
Vendors may only use names conforming to iana-vendor-tag at the
current time, future revisions of this specification may change this.
To: iana@iana.org
Subject: Registration of ACAP vendor subtree
Private Prefix: vendor.name
Person and email address to contact for further information:
(company names and addresses should be included where appropriate)
4.1. Example Registration
IANA is requested to add the following registration, for use by
specification authors in examples, similarly to the domains specified
in [EXAMPLES]:
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To: iana@iana.org
Subject: Registration of ACAP vendor subtree
Private Prefix: vendor.example
Person and email address to contact for further information:
Dave Cridland <dave.cridland@isode.com>
5. Security Considerations
There are no known security issues with this registry. Individual
protocols using vendor subtree names may have security issues, and
the introduction of Unicode has in itself security implications - the
restriction of this is thought to mitigate these.
6. Acknowledgements
Thanks must go to Chris Newman, John Myers, and the other designers
of ACAP for the initial creation of the registry. Thanks also to
Alexey Melnikov for advice on this revision.
7. References
7.1. Normative References
[ABNF] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008.
[KEYWORDS]
Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[UTF-8] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003.
7.2. Informative References
[ACAP] Newman, C. and J. Myers, "ACAP -- Application
Configuration Access Protocol", RFC 2244, November 1997.
[ANNOTATE]
Daboo, C. and R. Gellens, "Internet Message Access
Protocol - ANNOTATE Extension", RFC 5257, June 2008.
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[EXAMPLES]
Eastlake, D. and A. Panitz, "Reserved Top Level DNS
Names", BCP 32, RFC 2606, June 1999.
[METADATA]
Daboo, C., "The IMAP METADATA Extension", RFC 5464,
February 2009.
Author's Address
Dave Cridland
Isode Limited
5 Castle Business Village
36, Station Road
Hampton, Middlesex TW12 2BX
GB
Email: dave.cridland@isode.com
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