Attributes can be implicitly or explicitly specified. Any attribute which has been explicitly specified is called an explicit attribute. If an attribute has not been specified explicitly, then the attribute takes on the default specification. Such an attribute is known as an implicit attribute.
For example, the usage of a data item need not be specified, in which case a data item's usage is DISPLAY
, unless the PICTURE character-string contains a "G" or an "N", in which case a data item's usage is DISPLAY-1