Level-Numbers

A system of level-numbers shows the organization of elementary items and group items. Since records are the most inclusive data items, level-numbers for records start at 01. Less inclusive data items are assigned higher (not necessarily successive) level-numbers not greater in value than 49. There are special level-numbers, 66, 77, 78, and 88, which are exceptions to this rule. Separate entries are written in the source program for each level-number used.

A group includes all group and elementary items following it until a level-number less than or equal to the level-number of that group is encountered. All items which are immediately subordinate to a given group item must be described using identical level-numbers greater than the level-number used to describe that group item.

Four types of entries exist for which there is no true concept of level. These are:

1.	Entries that specify elementary items or groups introduced by a RENAMES clause.

2.	Entries that specify noncontiguous working storage and linkage data items.

3.	Entries that specify condition-names.

4.	Entries that specify constants.

Entries describing items by means of RENAMES clauses for the purpose of re-grouping data items have been assigned the special level-number 66.

Entries that specify noncontiguous data items, which are not subdivisions of other items, and are not themselves subdivided, have been assigned the special level-number 77.

Entries that specify constant names have been assigned the special level-number 78.

Entries that specify condition-names, to be associated with particular values of a conditional variable, have been assigned the special level-number 88.