%% You should probably cite draft-khatri-sipcore-call-transfer-fail-response-05 instead of this revision.
@techreport{khatri-sipcore-call-transfer-fail-response-00,
    number =    {draft-khatri-sipcore-call-transfer-fail-response-00},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-khatri-sipcore-call-transfer-fail-response/00/},
    author =    {Shrawan Kumar Khatri and Vikram Singh and Marcelo Pazos and Cherng-Shung Hsu and Yong Xie},
    title =     {{A SIP Response Code (497) for Call Transfer Failure}},
    pagetotal = 10,
    year =      ,
    month =     ,
    day =       ,
    abstract =  {This document defines the 497 (Call Transfer Failure) SIP response code, allowing Call Pull and Call Push parties to indicate that the operation was rejected. Optional warning codes are defined to carry granular information. SIP entities may use this information to adjust how subsequent calls can be handled intelligently.},
}