%% You should probably cite draft-ietf-sip-certs instead of this I-D.
@techreport{ietf-sipping-certs-03,
    number =    {draft-ietf-sipping-certs-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-ietf-sipping-certs/03/},
    author =    {Cullen Fluffy Jennings and Jon Peterson},
    title =     {{Certificate Management Service for The Session Initiation Protocol (SIP)}},
    pagetotal = 29,
    year =      2006,
    month =     mar,
    day =       7,
    abstract =  {This draft defines a Credential Service that allows Session Initiation Protocol (SIP) User Agents (UAs) to use a SIP package to discover the certificates of other users. This mechanism allows user agents that want to contact a given Address-of-Record (AOR) to retrieve that AOR's certificate by subscribing to the Credential Service. The Credential Service also allows users to store and retrieve their own certificates and private keys.},
}