Level Number

In addition, it is used to identify entries for working-storage items, linkage items, condition-names

, constant-names

and the RENAMES clause.

General Format

A level-number is required as the first element in each data description entry.
Data description entries subordinate to an FD or SD entry must have level-numbers with the values 01 through 49, 66
,78

or 88. (See the topic File Description Entry Skeleton.)
Data description entries in the Report Section and Screen Section must have level-numbers with the values 01 through 49
, or 78
Data description entries in the Working-Storage Section
, Local-Storage Section

and Linkage Section must have level-numbers with the values 01 through 49, 66, 77

, 78

or 88.
A level-number can be a one- or two-digit number.

The level-number 01 identifies the first entry in each record description.
Special level numbers have been assigned to certain entries where there is no real concept of level hierarchy:
1. The level-number 77 is assigned to identify noncontiguous working-storage data items and noncontiguous linkage data items. It can be used only as described by Format 1 of the data description skeleton earlier in this chapter.
2. Level number 66 is assigned to identify RENAMES entries and can be used only as described in Format 2 of the data description skeleton earlier in this chapter.
3. Level number 88 is assigned to entries which define condition-names associated with a conditional variable and can be used only as described in Format 3 of the data description skeleton earlier in this chapter.
4. Level number 78 is assigned to entries which define constant-names. It can be used only as described in Format 4 of the data description skeleton earlier in this chapter.
Multiple level 01 entries subordinate to an FD or SD entry represent implicit redefinitions of the same area.