Briefing Package for URI Activity

This briefing package was created in the context of the W3C Process Document and Guidebook for Working Group Chairs.

1. Executive Summary

The most fundamental specification of Web architecture, while one of the simpler, is that of the Universal Resource Identifier, or URI. The principle that anything, absolutely anything, "on the Web" should be identified distinctly by an otherwise opaque string of characters is core to the universality. -- Web Architecture from 50,000 feet, Tim Berners-Lee

Recently there have been renewed efforts to use URI's in new ways for new types of resources:

• Persistent identifiers and resolution services are intended to solve the ever growing problem of broken links. We would also like to avoid the need for any centralized registry mechanisms by using URIs as globally unique, persistent identifiers.

• Many new URI schemes have been proposed for new or existing protocols and new kinds of semantics for interacting with internet resources are being explored. The Internet Engineering Task Force (IETF) is working on guidelines for and registration of new schemes, but it is important to note that very few schemes beyond those available at the origin of the web have been deployed. We need to either promote deployment of new URI schemes or avoid the need for any new schemes while maintaining extensiblity to support new protocols.

• New resource types are being defined, such as XML, XHTML, SVG, SMIL, and RDF, that use URIs to identify new kinds of resources, such as internal elements, nodes of data graphs, and name spaces. In addition to the simple one-way link relationship, where the referenced resource "replaces" the current resource when the user directs, many other link relationships between multiple resources are being explored in the XML Linking Activity.

• Metadata about resources and metadata about identifiers should also be treated as resources, with their own identifers. An identifier can be treated as metadata for how to find the resource it identifies, and metadata itself can be treated as a "descriptive identifier" for the collection of resources for which it applies. Unambiguous identifiers are required in declarations of intellectual property rights, privacy policies, and to allow reference to many non-internet resources. This close relationship between identifiers and metadata needs to be explored.

All these issues, and more, are effectively calling into question our early concepts of identifiers and resources; it is time to reexamine these fundamental concepts to develop a deeper, more comprehensive understanding. Please see the proposed URI Activity Statement for more detailed discussion of these issues.

2. Background

(Answers to questions concerning a new activity in the process document)

What is the market within the area of the proposal? Who or what group wants this (providers, users, etc.)?

The target market of the activity includes those who want to promote standardized access to internet resources of all kinds, and decentralized registration and resolution of identifiers.

What community will benefit from this activity? Are members of this community part of W3C now? If not, will they join the effort?

Current W3C members will benefit from this activity at least indirectly by facilitating focused work on URIs that benefits other W3C activities related to identifiers. Non-W3C members who have an incentive to make resources internet accessible would benefit (and may then wish to join W3C). Where non-URI addressing schemes, centralized registries, and other informal naming scheme are currently used, providers may be willing to adopt URI addressing schemes instead if they see the benefits of internet-based registration and access. The global community of web users and providers will benefit when more of the world's resources become addressable via the one general URI mechanism.

Who or what currently exists in the market? Is the market mature/growing/developing a niche? What competing technologies exist? What competing organizations exist? What organizations are likely to be affected by potential overlap?

Potential competitors to URIs are any other naming schemes, of which there are many. Naming schemes for internet resources are a prime concern, but fortunately, the strong influence of the web has encouraged the use of URIs instead of the alternatives. But another concern is other internet-based naming schemes that use central registries. These require yet another administrative body to manage the registration, arbitration, and resolution services associated with the naming scheme. This would also be true of URI schemes that don't leverage use of DNS for that purpose. IANA is a highly visible example of a registration authority for names and numbers associated with internet protocols.

IETF working groups concerned with URIs will likely be affected. URIs are often (but not necessarily) associated with internet protocols, and the standardization of those protocols may or may not happen within the IETF process. But the URIs associated with those protocols are often considered the domain of the web, since it was the WWW servers and browsers that popularized the use of URIs. Consequently, since the W3C is recognized as the leader of web standards development, people often look to us for advice and endorsement of URI schemes. Nevertheless, we will rely on continued coordination between the IETF and W3C to come to common agreement.

What Team resources will be consumed (technical and administrative)?

See Section "W3C Resource Statement" below.

What is the scope of the work?

See Section "Scope" in the URI-IG Charter for the scope of that particular activity, the only one proposed at this time.

What are initial timetables?

See Section "Duration and Milestones" in the URI-IG Charter.

Is there a window of opportunity that cannot be missed?

Although naming issues have existed long before the internet, URIs are well established now, at least for internet resources. Most issues should now be addressed on an on-going basis rather than in crisis mode.

What intellectual property (for example, an implementation) must be available for licensing and is this intellectual property available for a reasonable fee and in a non-discriminatory manner?

No IPR is known to be needed for processes or standards related to URIs.

How might a potential Recommendation interact and overlap with existing international standards and Recommendations?

No Recommendations are anticipated from this activity at this time.

Is this activity likely to fall within the dominion of an existing group?

See Section "Current W3C Status" below.

Should new groups be created? How should they be coordinated?

See Section "Proposal: URI Activity" below.

3. Current W3C Status

Presently, there is no activity at W3C concerned specifically with URIs. Most, if not all, current W3C activities and working groups involve identifiers in one way or another. The IETF also has several groups involved with identifiers of internet resources, and central registries of identifiers. But none of these groups has as their principle focus the general understanding of URIs and resources and how that relates to other web architecture issues.

4. Proposal: URI Activity

This Briefing Package calls for the instantiation of a URI Activity with a single Chartered Interest Group at its outset. A possible deliverable of this IG will be charters for additional work if necessary, which will be sent to the W3C membership for review and approval.

Proposed URI Activity

We propose to start a W3C URI Activity that will be part of the Architecture domain with strong ties to the Technology and Society domain. Please see the Proposed URI Activity Statement

Proposed URI Interest Group

Please see the Proposed URI Interest Group Charter

Resource statement

W3C resource commitment

The Interest Group will have a W3C staff contact (who might serve as co-chair). It is expected that this commitment (including participation in any WGs that must be coordinated with) will take 20% of staff time. This commitment is mostly tied to participation in the URI Interest Group and other related architecture and metadata WGs.

Staff funding for this work will come from W3C membership dues.

Member resource commitment

Since participation in the URI Interest Group is open to non-members, there is no minimum member commitment.