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

    Puts the display in a file and queues the file to SYS$PRINT for
    printing under the name given by the /OUTPUT qualifier. If you
    do not specify the /OUTPUT qualifier, output is directed to a
    temporary file named DIRECTORY.LIS, which is queued for printing
    and then is deleted.