%% You should probably cite rfc4969 instead of this I-D.
@techreport{ietf-enum-vcard-06,
    number =    {draft-ietf-enum-vcard-06},
    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-vcard/06/},
    author =    {Alexander Mayrhofer},
    title =     {{IANA Registration for vCard Enumservice}},
    pagetotal = 7,
    year =      2007,
    month =     mar,
    day =       22,
    abstract =  {This memo registers the Enumservice "vCard" using the URI schemes "http" and "https". This Enumservice is to be used to refer from an ENUM domain name to a vCard instance describing the user of the respective E.164 number. Information gathered from those vCards could be used before, during, or after inbound or outbound communication takes place. For example, a callee might be presented with the name and association of the caller before picking up the call. {[}STANDARDS-TRACK{]}},
}