| Format 3: NULL value |
|---|
|
This format assigns an invalid address as the initial value of an item defined as USAGE POINTER, USAGE PROCEDURE POINTER, or USAGE FUNCTION-POINTER. It also assigns an invalid object reference as the initial value of an item defined as USAGE OBJECT REFERENCE.
VALUE IS NULL can be specified only for elementary items described implicitly or explicitly as USAGE POINTER, USAGE PROCEDURE-POINTER, USAGE FUNCTION-POINTER, or USAGE OBJECT REFERENCE.