@misc{rfc6664,
    series =    {Request for Comments},
    number =    6664,
    howpublished =  {RFC 6664},
    publisher = {RFC Editor},
    doi =       {10.17487/RFC6664},
    url =       {https://www.rfc-editor.org/info/rfc6664},
    author =    {Jim Schaad},
    title =     {{S/MIME Capabilities for Public Key Definitions}},
    pagetotal = 19,
    year =      2012,
    month =     jul,
    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. "Online Certificate Status Protocol Algorithm Agility" (RFC 6277) details an example of where this is used. This document is not an Internet Standards Track specification; it is published for informational purposes.},
}