Source : Free On-Line Dictionary of Computing

RFC 1521
     
         An {RFC} defining {Multipurpose Internet
        Mail Extensions} (MIME).  This {RFC} has been obsoleted by
        {RFC 2045}, {RFC 2046}, {RFC 2047}, {RFC 2048}, {RFC 2049},
        and {BCP0013}.
     
        {(rfc:1521)}.
     
        (1997-11-23)