%% You should probably cite rfc8496 instead of this I-D.
@techreport{york-p-charge-info-08,
    number =    {draft-york-p-charge-info-08},
    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-p-charge-info/08/},
    author =    {Dan York and Tolga Asveren},
    title =     {{P-Charge-Info: A Private Header Field (P-Header) Extension to the Session Initiation Protocol (SIP)}},
    pagetotal = 11,
    year =      2018,
    month =     jun,
    day =       30,
    abstract =  {This text documents the current usage of P-Charge-Info, an existing Session Initiation Protocol (SIP) private header field (P-Header) used to convey billing information about the party to be charged. This P-Header is currently used in production by several equipment vendors and carriers and has been in use since at least 2007. This document details the registration of this header field with IANA.},
}