W3C - DIWG Comments on
Architecture of the World Wide Web
Working Draft
February 2004
Scenarios appear to be based on "static" URI's; i.e.: "persistent" URI's (reference chapter 3.6.2). Suggest discussion of "dynamically generated" URI's; particularly addressing situations where dynamic URI's are bookmarked or forwarded by a user.
The statement "one might reasonably create URI's that ..." in the following passage may be inappropriate, as the preference for viewing a resource in Italian or Spanish should be communicated as meta information within the context, for which mechanisms such as CC/PP are being developed. To countenance the use of non-unique URI's for such a purpose is unwise.
URI producers need be conservative about the number of different URI's they produce for the same resource. For example, the parties responsible for weather.example.com should not use both "http://weather.example.com/Oaxaca" and "http://weather.example.com/oaxaca" to refer to the same resource; agents will not detect the equivalence relationship by following specifications. On the other hand, there may be good reasons for creating similar-looking URI's. For instance, one might reasonably create URI's that begin with "http://www.example.com/tempo" and "http://www.example.com/tiempo" to provide access to resources by users who speak Italian and Spanish.
Suggest discussion of accessing different representations (i.e.: transformed) of the same URI. This relates to Device Independence Principles DIP-1 (Device Independent Access) and DIP-2 (Device Independent Web Page Identifiers). Mention of HTTP Content Negotiation appears insufficient.
Suggest discussion on the limitations of Internet media types as the prime mechanism for selecting between different representations of a resource.
The fact that media type identifiers ("image/svg+xml" etc) do not contain version information seems to reduce the value of the good practice of providing version information in language instances (section 4.2.1). Should a user agent that understands only version 1 of a language be able to select between representations of a resource that are available using either version 1 or version 2? There seems little point in offering old as well as new language versions of a resource if there is no way for a server to know which to deliver.
It is understood that this is just a special case of expanding content negotiation to include broader delivery context information. But more work is needed before this can become an accepted part of the Web architecture.
Appreciative of the fact that work of the DIWG is recognized and DI Principles are referred to.