%% You should probably cite rfc2632 instead of this I-D.
@techreport{ietf-smime-cert-08,
    number =    {draft-ietf-smime-cert-08},
    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-cert/08/},
    author =    {Blake C. Ramsdell},
    title =     {{S/MIME Version 3 Certificate Handling}},
    pagetotal = 13,
    year =      1999,
    month =     apr,
    day =       26,
    abstract =  {S/MIME (Secure/Multipurpose Internet Mail Extensions), provides a method to send and receive secure MIME messages. Before using a public key to provide security services, the S/MIME agent MUST certify that the public key is valid. S/MIME agents MUST use PKIX certificates to validate public keys as described in the Internet X.509 Public Key Infrastructure (PKIX) Certificate and CRL Profile. {[}STANDARDS-TRACK{]}},
}