%% You should probably cite draft-ietf-sip-join instead of this I-D.
@techreport{mahy-sip-join-and-fork-01,
    number =    {draft-mahy-sip-join-and-fork-01},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-mahy-sip-join-and-fork/01/},
    author =    {Rohan Mahy and Daniel Petrie},
    title =     {{The Session Inititation Protocol (SIP) 'Join' Header}},
    pagetotal = 14,
    year =      2002,
    month =     jul,
    day =       2,
    abstract =  {This document defines a new header for use with SIP multi-party applications and call control. The Join header is used to logically join an existing SIP dialog with a new SIP dialog. This primitive can be used to enable a variety of features, for example: 'Barge-In', answering-machine-style 'Message Screening' and 'Call Center Monitoring'. Note that definition of these example features is non- normative.},
}