/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.