These are the ON-units that can be used with ON-unit condition notification in CodeWatch. See the Open PL/I Language Reference Manual for details about each supported ON-unit.
| ANYCONDITION | KEY |
| AREA | OVERFLOW |
| ATTENTION | RECORD |
| CONDITION | SIZE |
| CONVERSION | UNDEFINEDFILE |
| ENDFILE | UNDERFLOW |
| ENDPAGE | USERCONDITION |
| ERROR | USERCONDITION(ss$_UNWIND) |
| FINISH | VAXCONDITION |
| FIXEDOVERFLOW | ZERODIVIDE |