Library /sys$common/syshlp/dbg$help.hlb DEBUG, CANCEL, SOURCE, Qualifiers, /MODULE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /MODULE=module-name

    Cancels the effect of a previous SET SOURCE/MODULE=module-
    name command in which the same module name and qualifiers were
    specified. (The /MODULE qualifier allows you to specify a unique
    directory search list, directory search method, or both, for
    the named module.) You can append one or more of the qualifiers
    listed above to the SET SOURCE/MODULE and CANCEL SOURCE/MODULE
    commands.

    If you issue a CANCEL SOURCE/MODULE command with additional
    qualifiers, you cancel the effect of the specified qualifiers
    on the module. If you issue an unqualified CANCEL SOURCE/MODULE
    command, the debugger no longer differentiates the module from
    any other module in your directories.