COBOL Manual for TNS/E Programs (H06.08+, J06.03+)

◦ SIGN Clause
The SIGN clause cannot be used for national data items.
◦ SYNCHRONIZED Clause
The SYNCHRONIZED clause cannot be used for national data items.
◦ BLANK WHEN ZERO Clause
The BLANK WHEN ZERO clause cannot be used for national data items.
◦ BASED Clause
The BASED clause can be used only with level-01 or level-77 data items in the
Working-Storage, Extended-Storage, or Linkage Sections. It cannot be specified in a data
description entry that includes the EXTERNAL clause or the REDEFINES clause.
• Clauses Applying Only to Elementary Data Items
The PICTURE, SYNCHRONIZED, JUSTIFIED, and BLANK WHEN ZERO clauses can be specified
only for an elementary data item.
• Allocation of Storage
Elementary Items
The description of an internal elementary item in the Working-Storage Section or
Extended-Storage Section causes allocation of storage space for that item unless that item
redefines another item, in which case that item shares the redefined item’s storage space.
◦
The description of an external elementary item causes allocation of storage space for that
item in space belonging to the run unit, outside the storage area of any individual program.
This space is shared by all programs that describe the external data item.
◦ Linkage Items
The description of an elementary item in the Linkage Section does not cause its allocation.
In this case, the item is allocated by some other program, or by the run unit, and is made
available to the current program with the SET statement or the CALL statement that causes
its execution.
◦ BASED Items
The description of a BASED item does not cause its allocation. In this case, the compiler
allocates an implicit pointer associated with the item, and the item’s storage is allocated
by the ALLOCATE statement, or the item is associated with other storage by the SET
statement.
◦ Data Structures
The description of a data structure in the Working-Storage Section or Extended-Storage
Section does not cause any direct allocation, because its data-name merely designates
the combined storage spaces of all the elementary items subordinate to it; however, the
storage alignment requirements of some elementary items can cause the generation of
implicit FILLER items whose storage space also belongs to the containing data structures
(for details, see SYNCHRONIZED Clause).
◦ Data Items in the File Section
Technically, the data description entries in the File Section only establish descriptions of
data items in record areas—they are not declarations in the purest sense. If the file
Descriptions of Records (Levels 01-49) 185