/ENCODING=type

    This qualifier controls the type of decoding used to decode the
    input file. The possible values for this qualifier are BASE64,
    CBASE64 (gzip compressed BASE64), BASE85, BINHEX (encoding only,
    not the file format), BTOA, HEXADECIMAL, PATHWORKS, QUOTED_
    PRINTABLE, UUENCODE, CUUENCODE (gzip compressed UUENCODE). If the
    /HEADER qualifier is specified, then it should not be necessary
    to specify the encoding used as this should be given in the
    message header. The /ENCODING qualifier will override the header
    specification if it is used.