RFC 3553

RFC 3553: An IETF URN Sub-namespace for Registered Protocol Parameters 💖

okay bestie, let's do the paperwork first 📋✨ This is RFC 3553, and it's a Best Current Practice, so it's filed as BCP: 73 🌸 It came out in June 2003 from the Network Working Group, and the four authors are:

• M. Mealling at VeriSign 💜
• L. Masinter at Adobe Systems 🎀
• T. Hardie at Qualcomm 🦋
• G. Klyne at Nine by Nine 🍓

The category is Best Current Practice, and the title block doesn't list anything it obsoletes or updates, so it's standing on its own 🧚

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Status of this Memo ✨

This document is an Internet Best Current Practices doc for the Internet Community, and it's asking for discussion and suggestions for improvements. Distribution of this memo is unlimited 🫶

Copyright Notice 📜

Copyright (C) The Internet Society (2003). All Rights Reserved.

Abstract 🌈

This doc describes a new sub-delegation for the 'ietf' URN namespace for registered protocol items. The 'ietf' URN namespace is defined in RFC 2648 as a root for persistent URIs that refer to IETF-defined resources 💅

1. Introduction ✨

okay so, from time to time IETF standards need protocol elements registered in a well known central repository 🗂️ The Internet Assigned Numbers Authority (IANA) keeps that repository and takes direction from the IETF on what, how and when to add items to it. The IANA maintains lists of things like all assigned port numbers, MIME media types, enterprise numbers, etc. 🔥

Over time, people needed to reference these elements as URIs in various schema. In the past this was done in a very ad hoc way, and that easily led to interoperability problems 💀 So this document creates a new sub-delegation below the "ietf" [2]URN namespace [1] called 'params' 👑 It works as a standardized way of naming the items registered for IETF standards. Any assignments below that are specified in an RFC according to the IETF consensus process, and which include the template found in Section 4, are the ones we're talking about 💖

2. Terminology 🎀

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 🦋

3. IETF Sub-namespace Specifics 🧚

Here are the main details, bestie 💜

Sub-namespace name

The name is:

params

Declared registrant of the namespace

The Internet Engineering Task Force is the declared registrant 👑

Declaration of structure

The namespace is mostly opaque 🫧 The IANA, as the operator of the registry, may take suggestions for names to assign, but they reserve the right to assign whatever name they desire, within guidelines set by the IESG. The colon character (":") is used to show a very limited concept of hierarchy. If a colon is present, then the items on both sides of it are valid names. In general, if a name has a colon, the item on the left hand side represents a class of those items that would contain other items of that class 🌸

For example, a name can be assigned to the entire list of DNS resource record type codes, as well as to each individual code. The URN for the list might look like this:

urn:ietf:params:dns:rr-type-codes

while the URN for the SOA records type code might look like this:

urn:ietf:params:dns:rr-type-codes:soa

Relevant ancillary documentation

[3], [2], [1]

Identifier uniqueness considerations

The IESG uses the IETF consensus process to make sure that sub-namespaces generate unique names within that sub-namespace. The IESG delegates to the IANA the job of making sure the sub-namespace names themselves are unique. Until and unless the IESG specifies otherwise, the IANA is directed to ensure uniqueness by comparing the name to be assigned with the list of previously assigned names. If there's a conflict, the IANA has to request a new string from the registrant until the conflict is resolved 🔥

Identifier persistence considerations

This part is so important, bestie 😭 Once a name has been allocated, it MUST NOT be re-allocated for a different purpose. The rules for assignments of values within a sub-namespace MUST be constructed so that the meaning of values cannot change. This registration mechanism is not appropriate for naming values whose meaning may change over time. If a value changes over time, the assignment MUST name the container or concept that contains the value, not the value itself. For example, if a parameter called 'foo' has a value that changes over time, it's valid to create the name urn:ietf:params:foo-params:foo, which identifies that 'slot'. It is not valid to actually create a name that contains that value, unless it is a persistent and unique value such as a version number 💅

urn:ietf:params:foo-params:foo

Name the slot, not the value that changes inside it. That's the whole vibe 🙈

Process of identifier assignment

Identifiers are only assigned after a particular protocol element or number has been registered with the IANA using standard policies and procedures, or has been documented in an RFC describing a standards track protocol. So the 'gating' function for assignment is the "IETF Consensus" process documented in RFC 2434 [4] 🫶

Process of identifier resolution

At this time, no resolution mechanism is defined 🌈

Rules for Lexical Equivalence

Lexical equivalence is achieved by exact string match according to the rules for URN syntax found in RFC 2141 [1]. Specifically, because of the URN syntax definitions, the 'stringprep' standard found in RFC 3454 [7] does not apply 🦋

Conformance with URN Syntax

There are no additional characters reserved ✨

Validation mechanism

None 💤

Scope

Global 🌍

4. Assigning Names 🎀

Making a new registry name is going to be simple for most flat registries 💖 The only required elements are:

• the registry name,
• a reference to relevant documents,
• a statement about which current/proposed document repositories contain the authoritative data for the registry, and
• a statement specifying which element in the registry is the value to be used in the URN.

In most cases, that last element will be the index value assigned by the IANA 🧚

More complex registries (DNS Parameters for example) will need to repeat that information for any sub-namespaces. It should also be clear whether or not a name is assigned to the sub-namespace itself. For example, is urn:ietf:params:dns:rr-types valid by itself, and if so, what does it name? 🤔

The template goes like this:

• Registry name: the name of the sub-namespace. In many cases this should be the same name that the IANA calls the registry itself 🌸
• Specification: relevant IETF published documents that define the registry and the items in it 📜
• Repository: a pointer to the 'current' location of the registry in the protocol parameters repository, or the relevant RFCs that document the items being named. This value will change over time as the entity that maintains the repository moves files and/or fileservers. It is not meant as a permanent binding to the filename, but as a hint to the IANA for what the initial mapping would be 🗃️
• Index value: a description of how a registered value is to be embedded in the URI form. This MUST include details of any transformations that may be needed for the resulting string to conform to URN syntax rules, and any canonicalization needed so that the case-sensitive string comparison yields the expected equivalences 🔥

The process for requesting that a URN be assigned is currently to put the above template, or a reference to it, in the IANA considerations section of the specifying document. Other, more automated processes may be proposed at a later time if demand requires it 💅

9. Authors' Addresses 🎀

okay so the squad behind this one is four people, and I need you to know where to find them 💅

Michael Mealling VeriSign 21345 Ridgetop Circle Sterling, VA 20166 US

EMail: michael@verisignlabs.com, michael@neonym.net URI: http://www.verisign.com

Larry Masinter Adobe Systems Incorporated 345 Park Ave San Jose, CA 95110 US

Phone: +1 408 536-3024 EMail: LMM@acm.org URI: http://larry.masinter.net

Ted Hardie Qualcomm, Inc. 675 Campbell Technology Parkway Suite 200 Campbell, CA U.S.A.

EMail: hardie@qualcomm.com

Graham Klyne Nine by Nine

EMail: GK-IETF@ninebynine.org URI: http://www.ninebynine.net/

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10. Full Copyright Statement 🌸

bestie, the legal bit, and it's giving very serious energy 🙈

Copyright (C) The Internet Society (2003). All Rights Reserved.

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.

The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement ✨

funding for the RFC Editor function is currently provided by the Internet Society 🫶