2.8.2 Trigger Condition
The use of a trigger condition is optional. If no test conditions are specified, the trigger will be unconditionally invoked. No conditions are allowed if "Open" or "Close" Trigger Points are used.
If the trigger is defined at field level, the conditions can only involve the field to which the trigger is being linked. If the trigger is defined at the file level, the conditions can involve any other real or virtual fields in the file to which the trigger is being linked.
Refer to:
Also See
Trigger Concepts in the