RFC 4246

International Standard Audiovisual Number (ISAN) URN Definition

📅 published February 2006, from ietf

International Standard Audiovisual Number (ISAN) URN Definition 🎬✨

okay bestie, so this is RFC 4246, and it's an Informational doc from February 2006 💅 It's written by M. Dolan (Michael Dolan) at TBT, and the header doesn't list anything it obsoletes or updates, so it's a standalone vibe 🦋 It's basically the official paperwork for defining the ISAN URN namespace, which is the way you give movies and TV shows a unique, international ID 🍿

Status of This Memo

This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. 🌸

Copyright Notice

Abstract

ISAN (International Standard Audiovisual Number) is a standard numbering system that gives audiovisual works a unique, international identity 🎞️ This document defines the formal Uniform Resource Name (URN) Namespace Identifier (NID) for ISAN, so it's basically the official name tag for these IDs 💖

   1. Introduction ....................................................2
   2. URN Namespace Definition Template ...............................2
   3. Formal Syntax ...................................................4
   4. Security Considerations .........................................4
   5. Namespace Considerations ........................................4
   6. Community Considerations ........................................4
   7. IANA Considerations .............................................5
   8. References ......................................................5
      8.1. Normative References .......................................5
      8.2. Informative References .....................................5

1. Introduction ✨

okay so this doc is the formal definition of the URN Namespace Identifier (NID) for ISAN. That's the whole thing, no notes 🫶

2. URN Namespace Definition Template 💅

this template follows [RFC3406], so it's giving structure, and it goes field by field:

Namespace ID: ISAN

Registration Information: Version 1, dated 2004 11 22 📅

Declared registrant of the namespace: the ISAN International Agency at 26 rue de St Jean, CH-1203 Geneva, Switzerland 🇨🇭 The contact is Mr. Patrick Attallah, Managing Director.

Declaration of structure: the identifier looks like URN:ISAN:<ISAN-NSS>, where ISAN-NSS follows the URN syntax rules from [RFC2141] and is further constrained by [ISO15706] and this document. There are two forms, one with a version extension and one without. The formal BNF is in Section 3 below. Examples of the two forms:

URN:ISAN:0123-1230-3210-2310-1

URN:ISAN:1881-66C7-3420-6541-9-9F3A-0245-U

Relevant ancillary documentation: ISAN, its syntax, uses and processes are all defined in [ISO15706] 📚

Identifier uniqueness considerations: the ISAN International Agency that issues the numbers guarantees uniqueness, and numbers are never re-assigned. no duplicates, no drama 🔒

Identifier persistence considerations: persistence is guaranteed by ISO Registration Authority processes and contracts with the ISAN International Agency 💜

Process of identifier assignment: the agency defines the details from time to time. In general, any approved entity can request an ISAN number by providing the required metadata and paying the registration fee 💸 The agency may also delegate parts of the registration process to regional or market-based Registration Agencies.

Process for identifier resolution: ISAN numbers are resolved by a direct or indirect lookup with the ISAN International Agency. At the time of writing, a non-commercial, manual system is available online at http://www.isan.org. The agency may change the resolution procedures from time to time.

Rules for Lexical Equivalence: the ISAN-NSS is unique because of how the agency manages numbers. It's case-insensitive, so upper and lower case characters are treated as identical 🔤

Conformance with URN Syntax: no special considerations. The syntax is fully conformant with [RFC2141] ✅

Validation mechanism: the check digits give you syntax integrity, and lookup is available through online and offline services from the ISAN International Agency 🧾

Scope: Global 🌍

3. Formal Syntax 🧚

this syntax uses augmented Backus-Naur Form (BNF) and pulls in elements defined in the URN Syntax [RFC2141]. It's derived from the syntax in [ISO15706], but it's constrained to prohibit the space character as a separator. no spaces allowed, bestie 🙅‍♀️

   <ISAN-NSS>     ::= <root> <episode> [version]

   <root>         ::= 3*(<hexnum> "-")

   <episode>      ::= <hexnum> "-" <check>

   <version>      ::= 2*("-" <hexnum>) "-" <check>

   <hexnum>       ::= 4*(<hex>)

   <check>        ::= <upper> | <lower> | <number>

Note that <hex>, <upper>, <lower>, and <number> are defined in [RFC2141] 🎯

4. Security Considerations 🔐

okay, real talk, this one is serious 😭 This document only defines the syntax and resolution authority for the ISAN numbers. The details of the resolution process, and the security of the assignment and resolution system processes, are defined outside this document by the ISAN International Agency, so they're out of scope here.

5. Namespace Considerations 🌈

ISAN is an external numbering system run by an external agency established by ISO. Other URN namespaces can encode any generic numbering system, but there's currently no direct encoding for ISAN. The MPEG-21 system is an example of such a namespace 🎥

ISAN numbers are reserved for identifying audiovisual works that have a moving visual component, or components related to such a work (for example, a subtitling track) 🎬

6. Community Considerations 💖

the primary registrants for ISAN numbers are producers and studios of audiovisual works, like movies and TV shows 🍿 It isn't limited to "major" works, since any bona fide entity can register any work, but the biggest benefits come from works that are widely distributed. The users range from the studios themselves to film and video archives and libraries, rights administrators, program guide services, and audience measurement services. On the Internet, its potential use is as an identifier for streaming media 📺✨

7. IANA Considerations 🦋

this document defines a URN NID registration to be entered into the IANA registry of URN NIDs. It specifically requests the NID, "ISAN". 📝

8. References 📚

8.1. Normative References

   [RFC2141]  Moats, R., "URN Syntax", RFC 2141, May 1997.

   [ISO15706] ISO 15706, Information and documentation - International
              Standard Audiovisual Number (ISAN)

8.2. Informative References

   [RFC3406]  Daigle, L., van Gulik, D., Iannella, R., and P.
              Faltstrom, "Uniform Resource Names (URN) Namespace
              Definition Mechanisms", BCP 66, RFC 3406, October 2002.

Author's Address 💌

   Michael Dolan
   TBT
   PO Box 190
   Del Mar, CA 92014 USA

   EMail: md.1@newtbt.com

Full Copyright Statement 🎀

This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights.

This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM 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.

Intellectual Property 🧾

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Acknowledgement 💕

Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). 🫶

📦 where this page comes from

ietf: rfc4246 2006-02
💖 girlified by claude-haiku-5-5 on 2026-10-16: a language model's rewrite of the original, under its terms