%% You should probably cite rfc4694 instead of this I-D.
@techreport{ietf-iptel-tel-np-11,
    number =    {draft-ietf-iptel-tel-np-11},
    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-iptel-tel-np/11/},
    author =    {James Yu},
    title =     {{Number Portability Parameters for the "tel" URI}},
    pagetotal = 15,
    year =      2006,
    month =     aug,
    day =       29,
    abstract =  {This document defines five parameters in the "tel" Uniform Resource Identifier (URI) to carry the number portability (NP)-related information. Those parameters can be passed to the next-hop network node after an NP database dip has been performed. {[}STANDARDS-TRACK{]}},
}