User-driven identity adoption
Refers to adoption of Yadis-enabled identities that is driven by the user, i.e. the individual (or organization) that owns the content at a particular identity URL hosted by some provider.
An example for this would be Joe Blogger, whose blogging account is at BigISP. If BigISP was oblivious to URL-based identity and did nothing to support Joe Blogger's desire to turn his blog URL into an identity URL, Joe blogger could simply add the X-Yadis-Location http-equiv header to his home page's HTML. BigISP wouldn't have to do anything.
Compare to provider-driven identity adoption.