%% You should probably cite rfc4648 instead of this I-D.
@techreport{josefsson-rfc3548bis-04,
    number =    {draft-josefsson-rfc3548bis-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-josefsson-rfc3548bis/04/},
    author =    {Simon Josefsson},
    title =     {{The Base16, Base32, and Base64 Data Encodings}},
    pagetotal = 18,
    year =      2006,
    month =     may,
    day =       12,
    abstract =  {This document describes the commonly used base 64, base 32, and base 16 encoding schemes. It also discusses the use of line-feeds in encoded data, use of padding in encoded data, use of non-alphabet characters in encoded data, use of different encoding alphabets, and canonical encodings. {[}STANDARDS-TRACK{]}},
}