/HEADER
       /NOHEADER (default)

    This qualifier controls whether or not the encoded file begins
    with a MIME-compliant header. /NOHEADER is the default. When
    /NOHEADER is used, the /ENCODING qualifier is usually needed
    to specify the encoding since it cannot be determined from the
    header. To decode material that begins with a MIME-compliant
    header, e.g., specifying the encoding used, use the /HEADER
    qualifier.