%% You should probably cite rfc1991 instead of this I-D.
@techreport{atkins-pgpformat-01,
    number =    {draft-atkins-pgpformat-01},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-atkins-pgpformat/01/},
    author =    {Philip Zimmermann and Derek Atkins and William Stallings},
    title =     {{PGP Message Exchange Formats}},
    pagetotal = 21,
    year =      1995,
    month =     oct,
    day =       19,
    abstract =  {This document describes the format of "PGP files", i.e., messages that have been encrypted and/or signed with PGP. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.},
}