Filename: draft-ietf-urn-ietf-00.txt

A system for Uniform Resource Names (URNs) must be capable of supporting new naming systems. As an example of the sort of information that needs to be supplied when proposing new namepsaces, this document presents a naming system based on the RFC family of documents (RFCs, STDs, and FYIs) developed by the IETF and published by the RFC editor. This namespace can be supported within the URN framework and the currently proposed syntax for URNs. 0. Document History and Status With the first draft of this document, the only issue that has occured on the list is the discussion on functional equivalence for this namespace (see section 1.5). There are currently two positions on this: the first is what is specified here, and the second is that there is no equivalency for this namespace, e.g. a resolver receiving a request must return ONLY the resource named by that request. Expires 11/97 [Page 1] INTERNET DRAFT URN Namespace for RFC series documents May 1997 1. Namespace Syntax Consistent with the URN syntax specification [1], each namespace must specify syntax related information that is specific to that namespace. This section covers these specifications. 1.1. Namespace Identifier (NID) The namespace identifier for this namespace is "ietf". 1.2. Namespace Specific String (NSS) The Namespace Specific String has the following ABNF [2] specification: NSS = family ":" number family = "rfc" | "std" | "fyi" number = 1*DIGIT DIGIT = %x30..%x39 The ABNF specification for "family" above is based on the current documents in the RFC family. As new document series are added to the IETF family by the IESG (or its successor), this ABNF specification will need to be updated. Any system intended to resolve names for this namespace should be written with the awareness that a new document series may be introduced at any time. 1.3. Additional Reserved Characters No characters in addition to those specified in [1] are reserved by this namespace. 1.4. Additional Lexical Equivalence Relations Note that the entire URN is case-insensitive, because of the defintion of the NSS. 1.5. Functional Equivalence Relations Rules for equivalence in this namespace are embedded in the document mappings maintained by the RFC Editor (the index files "rfcindex.txt", "fyi-index.txt", "std-index.txt"). A resource is equivalent to the set of resources implied by the "(Also...)" construct in these mappings. As an example, the URN "urn:ietf:rfc:1661" is equivalent to th URN "urn:ietf:std:51" because the "rfc-index.txt" map shows that RFC 1661 is also STD 51. However, Expires 11/97 [Page 2] INTERNET DRAFT URN Namespace for RFC series documents May 1997 the URN "urn:ietf:std:51" is equivalent to the SET of URNs"urn:ietf:rfc:1661" and "urn:ietf:rfc:1662" since the "std-index.txt"shows that STD 51 is also RFC 1661 and RFC 1662. Therefore, aresolver receiving a N2R request for "urn:ietf:std:51" MUST returneither STD 51 or BOTH RFC 1661 and RFC 1662.2. Security ConsiderationsBecause this namespace defines no additional reserved characters, itdoes not add any security considerations beyond those inherent fromthe existence of the reserved characters from [1]. Further, the definition of the NSS above does not use any of the reservedcharacters from [1], which means that resolvers for this namespacemay be considered "secure" in the sense that any escaping ofcharacters in the NSS MUST result in the resolver indicating that theURN has incorrect syntax.3. AcknowledgmentsThanks to various members of the URN working group for comments onearlier drafts of this document. This document is partiallysupported by the National Science Foundation, Cooperative AgreementNCR-9218179.4. ReferencesRequest For Comments (RFC) and Internet Draft documents are availablefrom and numerous mirror sites.[1]R. Moats, "URN Syntax," RFC 2141, May 5, 1997.[2]D. Crocker, P. Overell, "Augmented BNF for SyntaxSpecifications: ABNF," Internet Draft (work in pro-gress), January 1997.5. Author’s AddressRyan MoatsAT&T;15621 Drexel CircleOmaha, NE 68135-2358USAPhone: +1 402 894-9456EMail: [email protected] This Internet Draft expires November 30, 1997. Expires 11/97[Page 3] INTERNET DRAFT URN Namespace for RFC series documentsMay 1997 Expires 11/97[Page 4]