W3C RDF Core Working Group Charter

1. Purpose and Scope

This is the charter for an RDF Core Working Group, managed under the W3C Semantic Web Activity. Implementor feedback concerning the RDF Model and Syntax Recommendation points to the need for a number of fixes, clarifications and improvements to the specification of RDF's abstract model and XML syntax. There is also considerable interest in the exploration of alternative XML serialization mechanisms for RDF data. The role of the RDF Core WG is to prepare the way for such work by stabilizing the core RDF specifications. The RDF Core WG is neither chartered to develop a new RDF syntax, nor to reformulate the RDF model. However, the group is expected to re-articulate the RDF model and syntax specification in such a way as to better facilitate future work on alternative XML encodings for RDF.

The RDF Core WG is chartered to complete the work on RDF vocabulary description present in the RDF Schema Candidate Recommendation. The Working Group will address questions and issues raised on the public comments feedback list and the RDF Interest Group list during the Candidate Recommendation period and will produce an updated W3C specification. The specific type of Technical Report to publish; whether Working Draft, updated Candidate Recommendation, or Proposed Recommendation will be decided by consensus of the Working Group according to the number and nature of any changes that are made to the previous version.

Following the Cambridge Communique meeting, feedback received on the RDF Schema Candidate Recommendation, and ongoing discussions in the XML and RDF developer community, the RDF Core WG must provide an account of the relationships between the basic components of RDF (Model, Syntax, Schema) and the larger XML family of recommendations.

2. Requirements

RDF provides a common framework for representing metadata across many applications. The semantics and structure of many varieties of metadata will be specified by independent communities. RDF provides an infrastructure that is sufficiently general and flexible to support these disparate applications.

In order to support interoperability across these disparate applications, a clarification and re-articulation of the core RDF specifications is required. The RDF Core WG must address the issues raised on www-rdf-comments against the RDF Schema 1.0 Candidate Recommendation and the RDF Model and Syntax Recommendation.

Deployment Considerations

Backwards compatibility with existing RDF applications is a priority for the RDF Core Working Group. Since the web is in continuous operation, it is the responsibility of this working group to ensure graceful deployment of corrections to the RDF specifications by carefully considering both the impact of new RDF documents on extant software, and the impact of revised software on extant documents.

At the same time, since the web is growing rapidly, it is the responsibility of this group to not let near-term deployment considerations grossly increase the future costs (to implementors, authors, users, etc.) of new features.

RDF Model and Syntax Requirements

The RDF Core WG must address the issues listed in the RDF Issue Tracking document, liaising (via the Semantic Web Coordination Group) with other W3C groups where issues need to be addressed at a cross-WG level.

The RDF Core group must take into account the various formalizations of RDF that have been proposed since the publication of the RDF Model and Syntax Recommendation. The group is encouraged to make use both of formal techniques and implementation-led test cases throughout their work.

RDF Schema Requirements

The goal of RDF Schema is to support an incrementally extensible approach to representing semantics in machine understandable form and to provide a simple base that can be extended by more powerful representational systems. The RDF schema system must provide an extensibility mechanism to allow future work (for example on Web Ontology and logic-based Rule languages) to provide richer facilities.

RDF Schema must be expressed in terms of the RDF model, and must use W3C RDF syntax. RDF Schema must use and build upon XML Schema datatypes to the fullest extent that is practical and appropriate. Specifically, the RDF Core Working Group is not chartered to develop a separate data typing language that duplicates facilities provided by XML Schema data types.

3. Relationships and Dependencies

Coordination with other groups will be managed through the Semantic Web Coordination Group.

The Topic Maps community have produced an XML-based Topic Map serialization syntax (XTM), and the W3C XML Protocol Working Group is already chartered to produce a similar mechanism. The XML Protocol Working Group Charter lists as a goal the creation of a "mechanism for serializing data representing non-syntactic data models such as object graphs and directed labeled graphs, based on the datatypes of XML Schema". The RDF Core WG will need to liaise with the XML Protocol Working Group and XTM communities to ensure that the RDF Core specifications are produced with consideration for possible future work on alternate RDF syntaxes.

4. Deliverables

The RDF Core WG is expected to begin work upon announcement of the Semantic Web Activity, and to meet face to face between two and four times prior to completion of their work in January 2002.


The deliverables of RDF Core WG are as follows.


The following schedule is planned. Revisions of this schedule must be agreed through the Semantic Web Coordination Group.

The group is expected to close down in early 2002.

5. Meetings and WG Membership

The Working Group will conduct its primary discussion via electronic mail. The mail archive will be publicly readable, however posting to the mailing list will be restricted to Working Group participants. Public input should be via the www-rdf-comments list, to which this Working Group will be expected to read and respond.

Working Group members will need to be familiar with the RDF Model and Syntax Specification, RDF Schema 1.0 Specification, and other related XML specifications (particularly XML Schema), and will ideally have implementation experience with RDF-based applications.

Teleconferences and face to face meetings will be scheduled as necessary to facilitate the work. Two to four face to face meetings are anticipated. Participants will be expected to typically devote a minimum of twelve hours per week, exclusive of face-to-face meetings, to this working group. Maintaining communication with the wider RDF developer community through RDF Interest Group channels (www-rdf-interest, www-rdf-logic, IRC chat) will also be important aspects of the group's work.

Participation in the Working Group is available to individuals nominated by their W3C Advisory Representatives. The Working Group chairs may grant invited expert status to other members of the Web community at their discretion.

6. Intellectual Property

W3C promotes an open working environment. Whenever possible, technical decisions should be made unencumbered by intellectual property right (IPR) claims. W3C's policy for intellectual property is set out in section 2.2 of the W3C Process Document.

Members participating in this Working Group are expected to disclose any intellectual property they have in this area. Any intellectual property essential to implement specifications produced by this Activity must be available on a royalty-free basis. At the suggestion of the Working Group, and at the discretion of the W3C Director, possibly requiring overall review by the Advisory Committee, technologies may be accepted if they are licensed on reasonable, non-discriminatory terms.

Members disclose patent and other IPR claims by sending email to an archived mailing list that is readable by Members and the W3C Team: http://lists.w3.org/Archives/Member/patent-issues/ (Member-only) . Members must disclose all IPR claims to this mailing list but they may also copy other recipients. Patent disclosures considered relevant to the specification produced by the Working Group will be made public.

7. Contacts

The chairs of the group are Brian McBride (HP Labs) and Dan Brickley (W3C/ILRT)

The W3C staff contact is Eric Miller, Semantic Web Activity lead.

$Revision: 1.60 $ of $Date: 2001/03/28 14:11:30 $ by $Author: swick $