1 /ENCODING
/ENCODING=type This qualifier controls the type of encoding used to encode 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). BASE64 encoding is the default; this is also the default decoding type used by DECODE.
2 /FILENAME
/FILENAME /NOFILENAME (default) When used in conjunction with the /HEADER qualifier, this qualifier specifies that the filename should be included in the MIME headers generated. Only the name and extension portion of the file specification will be used; any node, device, directory, and version number information will be discarded. This qualifier does not specify the input file to use; only the name to use for the name parameter of the Content-type: header line and the filename parameter of the Content-disposition: header line. By default, no filename parameter is specified in the Content-type: or Content-disposition: header lines. Or if used with /ENCODING=UUENCODE, the /FILENAME qualifier causes the filename to be included on the "begin 600" line.
3 /HEADER
/HEADER /NOHEADER (default) This qualifier controls whether or not a MIME-compliant header is placed at the beginning of the output. /HEADER is the default. /NOHEADER is used to produce output suitable for use in non-MIME messaging applications. Note that all structural information about the file is lost when /NOHEADER is used.