The UAProf (User Agent Profile) specification is concerned with capturing capability and preference information for wireless devices.
UAProf is related to the Composite Capability/Preference Profiles Specification created by the World Wide Web Consortium.
A mobile handset sends a header within an http request, containing the URL to its UAProf.
Another approach to the problem is to combine real-time derived information, component analysis, manual data and UAProfiles to deal with the actual device itself rather than the idealised representation of "offline" approaches such as UAProf or WURFL.
The W3C MWI (Mobile Web Initiative) and the associated DDWG (Device Description Working Group), recognising the difficulty in collecting and keeping track of UAProfs and device handset information, and the practical shortcomings in the implementation of UAProf across the industry have outlined specifications for a Device Description Repository, in the expectation that an ecosystem of such Repositories will eventually eliminate the need for local device repositories in favour of a web service ecosystem.