%% You should probably cite rfc6664 instead of this I-D.
@techreport{ietf-pkix-pubkey-caps-06,
    number =    {draft-ietf-pkix-pubkey-caps-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-pkix-pubkey-caps/06/},
    author =    {Jim Schaad},
    title =     {{S/MIME Capabilities for Public Key Definitions}},
    pagetotal = 25,
    year =      2012,
    month =     apr,
    day =       30,
    abstract =  {This document defines a set of Secure/Multipurpose Internet Mail Extensions (S/MIME) Capability types for ASN.1 encoding for the current set of public keys defined by the PKIX working group. This facilitates the ability for a requester to specify information on the public keys and signature algorithms to be used in responses. An example of where this is used is is detailed in Online Certificate Status Protocol Algorithm Agility (RFC 6277).},
}