Causes the preprocessor to output warnings for any errors it finds, either to the .lst file if one is being produced or to the screen.
>>-.---.-.----.-WARN---.----.------------><
   +-/-+ |    +-W------+    |
         |                  |
         +-NO-.-WARN---.----+
              +-W------+
               	 None
| Default: | NOWARN | 
| Phase: | Syntax check | 
| $SET: | Initial |