%% You should probably cite rfc4355 instead of this I-D.
@techreport{ietf-enum-msg-05,
    number =    {draft-ietf-enum-msg-05},
    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-msg/05/},
    author =    {Lawrence W. Conroy and Rudolf Brandner and Richard Stastny},
    title =     {{IANA Registration for Enumservices email, fax, mms, ems, and sms}},
    pagetotal = 16,
    year =      2005,
    month =     may,
    day =       11,
    abstract =  {This document registers the Enumservices "email", "fax", "sms", "ems", and "mms" using the URI schemes 'tel:' and 'mailto:' as per the IANA registration process defined in the ENUM specification RFC 3761. {[}STANDARDS-TRACK{]}},
}