%% You should probably cite rfc8141 instead of this I-D.
@techreport{ietf-urnbis-rfc2141bis-urn-03,
    number =    {draft-ietf-urnbis-rfc2141bis-urn-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-ietf-urnbis-rfc2141bis-urn/03/},
    author =    {Alfred Hoenes},
    title =     {{Uniform Resource Name (URN) Syntax}},
    pagetotal = 36,
    year =      2012,
    month =     oct,
    day =       16,
    abstract =  {Uniform Resource Names (URNs) are intended to serve as persistent, location-independent, resource identifiers. This document serves as the foundation of the 'urn' URI Scheme according to RFC 3986 and sets forward the canonical syntax for URNs, which subdivides URNs into "namespaces". A discussion of both existing legacy and new namespaces and requirements for URN presentation and transmission are presented. Finally, there is a discussion of URN equivalence and how to determine it. This document supersedes RFC 2141. The requirements and procedures for URN Namespace registration documents are set forth in a companion document, RFC 3406bis (BCP 66).},
}