Related data items can be parts of a hierarchical data structure. A data item that does not have subordinate data items is called an elementary item. A data item that is composed of one or more subordinate data items is called a group item.
A record can be either an elementary item or a group item. A group item can be either an alphanumeric group item or a national group item.
For example, Customer-Record below is an alphanumeric group item that is composed of two subordinate alphanumeric group items (Customer-Name and Part-Order), each of which contains elementary data items. These groups items implicitly have USAGE DISPLAY. You can refer to an entire group item or to parts of a group item in MOVE statements in the PROCEDURE DIVISION as shown below:
Data Division.
File Section.
FD Customer-File
Record Contains 45 Characters.
01 Customer-Record.
05 Customer-Name.
10 Last-Name Pic x(17).
10 Filler Pic x.
10 Initials Pic xx.
05 Part-Order.
10 Part-Name Pic x(15).
10 Part-Color Pic x(10).
Working-Storage Section.
01 Orig-Customer-Name.
05 Surname Pic x(17).
05 Initials Pic x(3).
01 Inventory-Part-Name Pic x(15).
. . .
Procedure Division.
Move Customer-Name to Orig-Customer-Name
Move Part-Name to Inventory-Part-Name
. . .
You could instead define Customer-Record as a national group item that is composed of two subordinate national group items by changing the declarations in the DATA DIVISION as shown below. National group items behave in the same way as elementary category national data items in most operations. The GROUP-USAGE NATIONAL clause indicates that a group item and any group items subordinate to it are national groups. Subordinate elementary items in a national group must be explicitly or implicitly described as USAGE NATIONAL.
Data Division.
File Section.
FD Customer-File
Record Contains 90 Characters.
01 Customer-Record Group-Usage National.
05 Customer-Name.
10 Last-Name Pic n(17).
10 Filler Pic n.
10 Initials Pic nn.
05 Part-Order.
10 Part-Name Pic n(15).
10 Part-Color Pic n(10).
Working-Storage Section.
01 Orig-Customer-Name Group-Usage National.
05 Surname Pic n(17).
05 Initials Pic n(3).
01 Inventory-Part-Name Pic n(15) Usage National.
. . .
Procedure Division.
Move Customer-Name to Orig-Customer-Name
Move Part-Name to Inventory-Part-Name
. . .
In the example above, the group items could instead specify the USAGE NATIONAL clause at the group level. A USAGE clause at the group level applies to each elementary data item in a group (and thus serves as a convenient shorthand notation). However, a group that specifies the USAGE NATIONAL clause is not a national group despite the representation of the elementary items within the group. Groups that specify the USAGE clause are alphanumeric groups and behave in many operations, such as moves and compares, like elementary data items of USAGE DISPLAY (except that no editing or conversion of data occurs).
related concepts
Unicode and the encoding of language characters
National groups
related tasks
Using national data (Unicode) in COBOL
Using national groups
related references
FILE SECTION entries
Storage of national data
Classes and categories of group items
(COBOL for Windows Language Reference)
PICTURE clause
(COBOL for Windows Language Reference)
MOVE statement
(COBOL for Windows Language Reference)
USAGE clause
(COBOL for Windows Language Reference)