%% You should probably cite draft-ietf-tsvwg-behave-requirements-update instead of this I-D.
@techreport{penno-behave-rfc4787-5382-5508-bis-04,
    number =    {draft-penno-behave-rfc4787-5382-5508-bis-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-penno-behave-rfc4787-5382-5508-bis/04/},
    author =    {Reinaldo Penno and Simon Perreault and Mohamed Boucadair and Kengo Naito},
    title =     {{Network Address Translation (NAT) Behavioral Requirements Updates}},
    pagetotal = 15,
    year =      2013,
    month =     jan,
    day =       7,
    abstract =  {This document clarifies and updates several requirements of RFC4787, RFC5382 and RFC5508 based on operational and development experience. The focus of this document is NAPT44.},
}