%% You should probably cite draft-ietf-sip-sips instead of this I-D.
@techreport{audet-sip-sips-guidelines-04,
    number =    {draft-audet-sip-sips-guidelines-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-audet-sip-sips-guidelines/04/},
    author =    {Francois Audet},
    title =     {{Guidelines for the use of the SIPS URI Scheme in the Session Initiation Protocol (SIP)}},
    pagetotal = 44,
    year =      2006,
    month =     oct,
    day =       19,
    abstract =  {This document updates RFC3261 by providing clarifications, guidelines and new requirements concerning the use of SIPS URI Scheme in the Session Initiation Protocol (SIP).},
}