%% You should probably cite draft-ietf-core-http-mapping instead of this I-D.
@techreport{castellani-core-http-mapping-03,
    number =    {draft-castellani-core-http-mapping-03},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-castellani-core-http-mapping/03/},
    author =    {Angelo P. Castellani and Salvatore Loreto and Akbar Rahman and Thomas Fossati and Esko Dijk},
    title =     {{Best practices for HTTP-CoAP mapping implementation}},
    pagetotal = 42,
    year =      2012,
    month =     mar,
    day =       12,
    abstract =  {This draft aims at being a base reference documentation for HTTP-CoAP proxy implementors. It details deployment options, discusses possible approaches for URI mapping, and provides useful considerations related to protocol translation.},
}