diff options
Diffstat (limited to 'doc/rfc/rfc3688.txt')
-rw-r--r-- | doc/rfc/rfc3688.txt | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/doc/rfc/rfc3688.txt b/doc/rfc/rfc3688.txt new file mode 100644 index 0000000..cd136e7 --- /dev/null +++ b/doc/rfc/rfc3688.txt @@ -0,0 +1,451 @@ + + + + + + +Network Working Group M. Mealling +Request for Comments: 3688 VeriSign, Inc. +BCP: 81 January 2004 +Category: Best Current Practice + + + The IETF XML Registry + +Status of this Memo + + This document specifies an Internet Best Current Practices for the + Internet Community, and requests discussion and suggestions for + improvements. Distribution of this memo is unlimited. + +Copyright Notice + + Copyright (C) The Internet Society (2004). All Rights Reserved. + +Abstract + + This document describes an IANA maintained registry for IETF + standards which use Extensible Markup Language (XML) related items + such as Namespaces, Document Type Declarations (DTDs), Schemas, and + Resource Description Framework (RDF) Schemas. + +1. Introduction + + Over the past few years, the Extensible Markup Language (XML) + [W3C.REC-xml] has become a widely used method for data markup. There + have already been several IETF Working Groups that have produced + standards that define XML Document Type Definitions (DTDs), XML + Namespaces [W3C.REC-xml-names], and XML Schemas [W3C.REC-xmlschema- + 1]. Each one of these technologies uses Uniform Resource Identifiers + (URIs) [RFC2396] and other standardized identifiers to identify + various components. + + For example, while it has been the practice within some standards + that use Document Type Definitions (DTDs) to forego the use of the + PUBLIC identifiers in favor of 'well known' SYSTEM identifiers, it + has proven to be more trouble than its worth to attempt to + standardize SYSTEM identifiers. The result is that several IETF + standards that have simply created non-resolvable URIs in order to + simply identify but not resolve the DTD for some given XML document. + + This document seeks to standardize and improve these practices by + creating an IANA maintained registry of XML element identifiers so + that document authors and implementors have a well maintained and + + + + +Mealling Best Current Practice [Page 1] + +RFC 3688 The IETF XML Registry January 2004 + + + authoritative location for their XML elements. As part of this + standard, the IANA will maintain: + + o the public representation of the document, + + o the URI for the elements if one is provided at the time of + registration, + + o a registry of Public Identifiers as URIs. + + In the case where the registrant does not request a particular URI, + the IANA will assign it a Uniform Resource Name (URN) that follows + [RFC3553]. + +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 BCP 14, RFC 2119 + [RFC2119]. + +3. Registerable Documents + +3.1. The Assigned/Registered URI + + All elements (except PUBLIC identifiers) in this registry will + require a URI in order to be registered. If the registrant wishes to + have a URI assigned, then a URN of the form + + urn:ietf:params:xml:<class>:<id> + + will be assigned where <class> is the type of the document being + registered (see below). <id> is a unique id generated by the IANA + based on any means the IANA deems necessary to maintain uniqueness + and persistence. NOTE: in order for a URN of this type to be + assigned, the item being registered MUST have been through the IETF + consensus process. Basically, this means that it must be documented + in a RFC. The RFC 3553 [RFC3553] URN registration template is found + in Section 6. + + The IANA will also maintain a file server available via at least HTTP + and FTP that contains all of the registered elements in some publicly + accessible file space in the same way that all of the IANA's + registered elements are available via + http://www.iana.org/assignments/. While the directory structure of + this server is up to the IANA, it is suggested that the files be + organized by the <class> and the individual files have the <id> as + their filename. + + + +Mealling Best Current Practice [Page 2] + +RFC 3688 The IETF XML Registry January 2004 + + + Implementors are warned that they should not programatically rely on + those resources being available or the directory structure remaining + static for any reason. It is explicitly recognized that some + software tools attempt to download DTDs, schema, etc., 'on the fly' + and that developers should understand when this is done and when to + not reference IANA network resources as a 'schema download + repository'. This is the reason that the IANA will not register or + provide SYSTEM identifiers. + +3.2. Registerable Classes + + The list of types of XML elements that can be registered with the + IANA are: + + publicid -- An XML document that contains a DOCTYPE declaration or + any other external reference can identify that reference via both + a PUBLIC identifier and a SYSTEM identifier. The SYSTEM + identifier is system-specific information that enables the entity + manager of an XML system to locate the file, memory location, or + pointer within a file where the entity can be found. It should + also be noted that a system identifier could be an invocation of a + program that controls access to an entity that is being + identified. Thus, they are not registered items. In many cases, + SYSTEM identifiers are also URIs. However, in these cases, the + URI is still only used for system-specific information. In the + case where a PUBLIC Identifier is also a URI, it is possible for + the SYSTEM Identifier to contain the same URI but this behavior is + not recommended unless its side effects are well known and + understood to not cause any unacceptable harm. + + A PUBLIC identifier is a name that is intended to be meaningful + across systems and different user environments. Typically, it + will be a name that has a registered owner associated with it, so + that public identifiers will be guaranteed unique and no two + entities will have the same public identifier. In practice, + PUBLIC identifiers are typically Formal Public Identifiers + [ISO.8879.1986] but they are not restricted to just that set. As + said in [RFC3151]: + + "Any string which consists only of the public identifier + characters (defined by Production 13 of Extensible Markup + Language (XML) 1.0 Second Edition) is a legal public + identifier." + + Therefore, it is legal for a PUBLIC identifier to be a URN if it + adheres to the character set restrictions. + + + + + +Mealling Best Current Practice [Page 3] + +RFC 3688 The IETF XML Registry January 2004 + + + Thus, the identifier registered along with a DTD is its PUBLIC + identifier. The only restriction being that it must adhere to the + character set restrictions. In the case where the registrant does + not provide one, the IANA will assign one of the form + 'urn:ietf:params:xml:pi:<id>'. Registrants are encouraged to + investigate RFC 3151 [RFC3151] as a recommended method for + minting a URN that can also be represented as an FPI. + + ns -- XML Namespaces [W3C.REC-xml-names] are named by a URI. They + have no real, machine-parseable representation. Thus, the + registered document will be either the specification or a + reference to it. In the case where a URI is not provided by the + registrant, the IANA will assign a URN of the form + 'urn:ietf:params:xml:ns:<id> which will be the XML Namespace's + name. + + schema -- XML Schemas [W3C.REC-xmlschema-1] are also identified by a + URI but their contents are machine parseable. The IANA registered + document will be the XML Schema file. The URN the IANA assigns + can be used as the URI for the schema and is of the form + 'urn:ietf:params:xml:schema:<id>'. + + rdfschema -- The Resource Description Format (RDF) + [W3C.CR-rdf-schema] is an XML serialization of a connected graph + based data model used for metadata expression. RDF makes use of + schemas for RDF that express grammars about relationships between + URIs. These grammars are identified by URIs. The URN assigned by + the IANA can be used as the identifying URI and is of the form + 'urn:ietf:params:xml:rdfschema:<id>'. + +4. Registration Procedures + + Until the IANA requests or implements an automated process for the + registration of these elements, any specifications must make that + request part of the IANA considerations section of their respective + documents. That request must be in the form of the following + template: + + URI + The URI or PUBLIC identifier that identifies the XML component. If + the registrant is requesting that the IANA assign a URI then this + field should be specified as "please assign". + + Registrant Contact + The individual/organization that is the registration contact for + the component being registered. Ideally, this will be the name + and pertinent physical and network contact information. In the + case of IETF developed standards, the Registrant will be the IESG. + + + +Mealling Best Current Practice [Page 4] + +RFC 3688 The IETF XML Registry January 2004 + + + XML + The exact XML to be stored in the registry. Unless the beginning + and end of the file is obvious, the document should use the text + "BEGIN" to mark the beginning of the file and "END" to mark the + end of the file. The IANA will insert any text between those two + strings (minus any page breaks and RFC formatting inserted by the + RFC Editor) into the file kept in the repository. + +5. Security Considerations + + The information maintained by the IANA will be authoritative and will + be a target for attack. In some cases, such as XML Schema and DTDs, + the content maintained by the IANA may be directly input into + software. Thus, extra care should be taken by the IANA to maintain + the security precautions required for an important reference location + for the Internet. + + Beyond this concern, there are no other security considerations not + already found with any other IANA registry. + +6. IANA Considerations + + This document seeks to create a rather large registry for which the + IANA (at the direction of the IESG) will be primarily responsible. + The amount of effort required to maintain this registry is not + insignificant and the policies and procedures surrounding any + approval process are non-trivial. The registry is on a First Come + First Served basis, but a Specification is Required. Once the IETF + has some experience with this registry, these policies may change. + + RFC 3553 [RFC3553] specifies that any new registry requiring a name, + to be assigned below the 'urn:ietf:params' namespace and must specify + the structure of that space in template form. The IANA has created + and will maintain this new sub-namespace: + + Registry-name: xml + + Specification: This document contains the registry specification. + The namespace is organized with one sub-namespace which is the + <id>. + + Repository: To be assigned according to the guidelines found above. + + Index value: The class name + + + + + + + +Mealling Best Current Practice [Page 5] + +RFC 3688 The IETF XML Registry January 2004 + + +7. Normative References + + [ISO.8879.1986] International Organization for Standardization, + "Information processing - Text and office + systems - Standard generalized markup language + (SGML)", ISO Standard 8879, 1986. + + [RFC2119] Bradner, S., "Key words for use in RFCs to + Indicate Requirement Levels", BCP 14, RFC 2119, + March 1997. + + [RFC2396] Berners-Lee, T., Fielding, R. and L. Masinter, + "Uniform Resource Identifiers (URI): Generic + Syntax", RFC 2396, August 1998. + + [RFC3151] Walsh, N., Cowan, J. and P. Grosso, "A URN + Namespace for Public Identifiers", RFC 3151, + August 2001. + + [RFC3553] Mealling, M., Masinter, L., Hardie, T. and G. + Klyne, "An IETF URN Sub-namespace for + Registered Protocol Parameters", BCP 73, RFC + 3553, June 2003. + + [W3C.CR-rdf-schema] Brickley, D. and R. Guha, "Resource Description + Framework (RDF) Schema Specification 1.0", W3C + CR-rdf-schema, March 2000, + <http://www.w3.org/TR/2000/CR-rdf-schema- + 20000327>. + + [W3C.REC-xml] Bray, T., Paoli, J., Sperberg-McQueen, C. and + E. Maler, "Extensible Markup Language (XML) 1.0 + (2nd ed)", W3C REC-xml, October 2000, + <http://www.w3.org/TR/REC-xml>. + + [W3C.REC-xml-names] Bray, T., Hollander, D. and A. Layman, + "Namespaces in XML", W3C REC-xml-names, January + 1999, <http://www.w3.org/TR/REC-xml-names>. + + [W3C.REC-xmlschema-1] Thompson, H., Beech, D., Maloney, M. and N. + Mendelsohn, "XML Schema Part 1: Structures", + W3C REC-xmlschema-1, May 2001, + <http://www.w3.org/TR/xmlschema-1/>. + + + + + + + + +Mealling Best Current Practice [Page 6] + +RFC 3688 The IETF XML Registry January 2004 + + +8. Intellectual Property Statement + + The IETF takes no position regarding the validity or scope of any + intellectual property or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; neither does it represent that it + has made any effort to identify any such rights. Information on the + IETF's procedures with respect to rights in standards-track and + standards-related documentation can be found in BCP-11. Copies of + claims of rights made available for publication and any assurances of + licenses to be made available, or the result of an attempt made to + obtain a general license or permission for the use of such + proprietary rights by implementors or users of this specification can + be obtained from the IETF Secretariat. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights which may cover technology that may be required to practice + this standard. Please address the information to the IETF Executive + Director. + +9. Author's Address + + Michael Mealling + VeriSign, Inc. + Mountain View, CA + USA + + EMail: michael@verisignlabs.com + URI: http://www.research.verisignlabs.com + + + + + + + + + + + + + + + + + + + + +Mealling Best Current Practice [Page 7] + +RFC 3688 The IETF XML Registry January 2004 + + +10. Full Copyright Statement + + Copyright (C) The Internet Society (2004). 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 assignees. + + 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. + + + + + + + + + + + + + + + + + + + +Mealling Best Current Practice [Page 8] + |