An internal table is characterized by the following four attributes during a type check.
During type declaration, this information may be missing or incomplete. The table type is then considered generic. Generic type specifications can only be used to type the formal parameters for subroutines, function modules, or methods.
Types of the table type ANY TABLE or INDEX TABLE are generic. For these table types, you cannot make a uniqueness specification with regard to the key.
The key specification may be missing. In this case, you cannot make a uniquenes specification.
The uniqueness specification is missing.
Internal table types