%% You should probably cite rfc4262 instead of this I-D.
@techreport{ietf-smime-certcapa-05,
    number =    {draft-ietf-smime-certcapa-05},
    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-smime-certcapa/05/},
    author =    {Stefan Santesson},
    title =     {{X.509 Certificate Extension for Secure/Multipurpose Internet Mail Extensions (S/MIME) Capabilities}},
    pagetotal = 5,
    year =      2005,
    month =     may,
    day =       26,
    abstract =  {This document defines a certificate extension for inclusion of Secure/Multipurpose Internet Mail Extensions (S/MIME) Capabilities in X.509 public key certificates, as defined by RFC 3280. This certificate extension provides an optional method to indicate the cryptographic capabilities of an entity as a complement to the S/MIME Capabilities signed attribute in S/MIME messages according to RFC 3851. {[}STANDARDS-TRACK{]}},
}