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

7 Data Division
The Data Division is optional in a COBOL program. It has four sections: the File Section, the
Working-Storage Section, the Extended-Storage Section, and the Linkage Section. Each section
contains entries describing data that the program unit being compiled from the source program
manipulates. If your program does not use the type of data that the section defines, then the section
is optional.
Data Categories and Data Descriptions
Table 31 Data Categories
Category
External DataInternal DataFile Data
Data that all programs in the run
unit can access
Data that a process develops
internally and holds in
temporary areas
Data that a process can read
from or write to files (including
the mapping between the
Definition
internal program storage and
the file storage)
File SectionWhere Data is
Described
File SectionWorking-Storage Section
Working-Storage SectionExtended-Storage Section
Extended-Storage SectionLinkage Section
File descriptions, record
description entries, and
independent data item entries
Record description entries and
independent data item entries
Data file description entries and
sort-merge file description
entries, each followed by one
How Data is
Described
or more record description
entries
Record Description Entries
A record description entry is a set of one or more data description entries. The first data description
entry has level number 01. Each additional entry has a level number in the range 02 through 49
or the special level number 66 or 88. Entries with level numbers 02 through 49 and 66 are
subordinate data items of the record data item defined in the initial data description entry (which
has level number 01). Entries with level number 66 redefine or rename portions of the record.
Entries with level number 88 define condition-names.
Data items with level number 77 do not belong to records.
Data Categories and Data Descriptions 153