VMS Help EXCHANGE, DIRECTORY, Qualifiers, /OUTPUT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /OUTPUT[=file-spec]

    Writes the DIRECTORY output to a specified file, rather than
    to the current SYS$OUTPUT device. If you specify the /OUTPUT
    qualifier without a file specification, the output is directed to
    SYS$OUTPUT. If you omit the file type in the file specification,
    the default file type is .LIS. If you specify a file type
    and omit the file name, the default file name is EXCHDIRE. No
    wildcard characters are allowed in the file specification.