%% You should probably cite draft-york-dispatch-p-charge-info instead of this I-D.
@techreport{york-sipping-p-charge-info-15,
    number =    {draft-york-sipping-p-charge-info-15},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-york-sipping-p-charge-info/15/},
    author =    {Dan York and Tolga Asveren},
    title =     {{P-Charge-Info - A Private Header (P-Header) Extension to the Session Initiation Protocol (SIP)}},
    pagetotal = 15,
    year =      2012,
    month =     aug,
    day =       31,
    abstract =  {This text documents 'P-Charge-Info', an existing private Session Initiation Protocol (SIP) header (P-header) used to convey billing information about the party to be charged. This P-Header is currently in production usage by a number of equipment vendors and carriers and this document is submitted to request the registration of this header with IANA. This P-Header may also be used in some situations to carry the ISUP Charge Number parameter for PSTN interconnection. IMPORTANT NOTE: This version of the Internet Draft will be the last with this name, as the SIPPING Working Group no longer exists. The next version of this Internet Draft will be through the DISPATCH Working Group and will be draft-york-dispatch-p-charge-info-00.},
}