Level Number
The level-number shows the hierarchy of data within a logical
record. In addition, it is used to identify entries for working-storage items,
linkage items, condition-names
, constant-names
and the RENAMES clause.
General Format

Syntax Rules
- 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.
General Rules
- 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:
- 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.
- 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.
-
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.
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.