%% You should probably cite draft-ietf-sipcore-rfc4244bis instead of this I-D.
@techreport{barnes-sipcore-rfc4244bis-03,
    number =    {draft-barnes-sipcore-rfc4244bis-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-barnes-sipcore-rfc4244bis/03/},
    author =    {Mary Barnes and Francois Audet and Shida Schubert and Hans Erik van Elburg and Christer Holmberg},
    title =     {{An Extension to the Session Initiation Protocol (SIP) for Request History Information}},
    pagetotal = 61,
    year =      2009,
    month =     oct,
    day =       26,
    abstract =  {This document defines a standard mechanism for capturing the history information associated with a Session Initiation Protocol (SIP) request. This capability enables many enhanced services by providing the information as to how and why a call arrives at a specific application or user. This document defines an optional SIP header, History-Info, for capturing the history information in requests.},
}