Depending on how a data item is defined, it belongs to one of the five following categories:
These categories are further grouped into the following classes:
Every elementary item is classified into one of these classes and categories by its PICTURE clause. Elementary items that do not have a PICTURE clause are in the numeric category.
Group items always belong to the alphanumeric category regardless of the categories of any elementary items they contain. A group item may be used in any place an alphanumeric item is allowed.