%% You should probably cite rfc7225 instead of this I-D.
@techreport{ietf-pcp-nat64-prefix64-04,
    number =    {draft-ietf-pcp-nat64-prefix64-04},
    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-pcp-nat64-prefix64/04/},
    author =    {Mohamed Boucadair},
    title =     {{Learning NAT64 PREFIX64s using PCP}},
    pagetotal = 15,
    year =      2013,
    month =     jul,
    day =       31,
    abstract =  {This document defines a new PCP extension to learn the IPv6 prefix(es) used by a PCP-controlled NAT64 device to build IPv4-converted IPv6 addresses. This extension is needed for successful communications when IPv4 addresses are used in referrals.},
}