%% You should probably cite rfc9165 instead of this I-D.
@techreport{ietf-cbor-cddl-control-06,
    number =    {draft-ietf-cbor-cddl-control-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-cbor-cddl-control/06/},
    author =    {Carsten Bormann},
    title =     {{Additional Control Operators for CDDL}},
    pagetotal = 13,
    year =      2021,
    month =     sep,
    day =       27,
    abstract =  {The Concise Data Definition Language (CDDL), standardized in RFC 8610, provides "control operators" as its main language extension point. The present document defines a number of control operators that were not yet ready at the time RFC 8610 was completed: .plus, .cat and .det for the construction of constants, .abnf/.abnfb for including ABNF (RFC 5234/RFC 7405) in CDDL specifications, and .feature for indicating the use of a non-basic feature in an instance.},
}