%% You should probably cite draft-ietf-sip-xcapevent instead of this I-D.
@techreport{urpalainen-sip-xcap-diff-event-03,
    number =    {draft-urpalainen-sip-xcap-diff-event-03},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-urpalainen-sip-xcap-diff-event/03/},
    author =    {Jari Urpalainen},
    title =     {{An Extensible Markup Language (XML) Configuration Access Protocol (XCAP) Diff Event Package}},
    pagetotal = 14,
    year =      2007,
    month =     nov,
    day =       16,
    abstract =  {This document describes an "xcap-diff" SIP event package, with the aid of which clients can receive notifications of the partial changes of Extensible Markup Language (XML) Configuration Access Protocol (XCAP) resources. The initial synchronization and document updates are based on using the XCAP-Diff format.},
}