A GROUP-USAGE clause with the NATIONAL phrase specifies that the group item defined by the entry is a national group item. A national group item contains national characters in all subordinate data items and subordinate group items.
When GROUP-USAGE NATIONAL is specified:
Unless stated otherwise, a national group item is processed as though it were an elementary data item of usage national, class and category national, described with PICTURE N(m), where m is the length of the group in national character positions.
Usage note: When you use national groups, the compiler can ensure proper truncation and padding of group items for statements such as MOVE and INSPECT. Groups defined without a GROUP-USAGE NATIONAL clause are alphanumeric groups. The content of alphanumeric groups, including any national characters, is treated as alphanumeric data, possibly leading to invalid truncation or mishandling of national character data.
The table below summarizes the cases where a national group item is processed as a group item.
| Language feature | Processing of national group items |
|---|---|
| Name qualification | The name of a national group item can be used to qualify the names of elementary data items and subordinate group items in the national group. The rules of qualification for a national group are the same as the rules of qualification for an alphanumeric group. |
| RENAMES clause | The rules for a national group item specified in the THROUGH phrase are the same as the rules for an alphanumeric group item specified in the THROUGH phrase. The result is an alphanumeric group item. |
| CORRESPONDING phrase | A national group item is processed as a group in accordance with the rules of the CORRESPONDING phrase. Elementary data items within a national group are processed the same as they would be if defined within an alphanumeric group. |
| INITIALIZE statement | A national group item is processed as a group in accordance with the rules of the INITIALIZE statement. Elementary items within the national group are initialized the same as they would be if defined within an alphanumeric group. |
| XML GENERATE statement | A national group item specified in the FROM phrase is processed as a group in accordance with the rules of the XML GENERATE statement. Elementary items within the national group are processed the same as they would be if defined within an alphanumeric group. |