%% You should probably cite rfc5067 instead of this I-D.
@techreport{ietf-enum-infrastructure-enum-reqs-04,
    number =    {draft-ietf-enum-infrastructure-enum-reqs-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-enum-infrastructure-enum-reqs/04/},
    author =    {Penn Pfautz and Steven D. Lind},
    title =     {{Infrastructure ENUM Requirements}},
    pagetotal = 7,
    year =      2007,
    month =     may,
    day =       21,
    abstract =  {This document provides requirements for "infrastructure" or "carrier" ENUM (E.164 Number Mapping), defined as the use of RFC 3761 technology to facilitate interconnection of networks for E.164 number addressed services, in particular but not restricted to VoIP (Voice over IP.) This memo provides information for the Internet community.},
}