/HELP_LIBRARY=file-spec

    Specifies the HELP file (.HLB file) where you can find help text
    for placeholders and tokens defined for this package. If omitted,
    then no HELP file is associated with the package.

    LSE applies the default file specification SYS$HELP:HELPLIB.HLB.
    If you want to access some device or directory other than
    SYS$HELP, you must supply an explicit device and directory name.