FREE MEMORY.
The syntax check performed in an ABAP Objects context is stricter than in other ABAP areas. See ID must be Specified
This statement releases an area in ABAP memory that was previously created
with EXPORT TO MEMORY.
An IMPORT ... FROM MEMORY would then return Return Code 4.
... ID key
Only the ABAP memory for ID key (character-type data object except strings) is released.
EXPORT TO MEMORY, IMPORT FROM MEMORY
Delete Data Cluster in Memory