Module function 

User-defined functions (FUNCTION-ID): the rules a definition or prototype keeps, the prototypes an invocation is checked against (Language Reference, the USING phrase’s conformance of parameters for user-defined functions), and the formal parameters and result the interpreter invokes one with.

Structs

Formal

A formal parameter or the RETURNING item: what an argument conforms to, and the shape of the temporary that holds a literal or expression argument.

Udf

A user-defined function as an invocation sees it.

Functions

check_invocation

The invocation of udf at f: its argument count, and each data-item argument against its formal parameter.

conformance

Why argument item of the caller’s layout does not conform to formal. A literal or an expression has no description to conform: it is moved or computed into a temporary of the formal parameter’s (assumption C272).

functions

The functions a program may invoke, each laid out once. A prototype that does not lay out is left out here: compiling it reports why, and an invocation of it is then unknown.

signature

The function as its prototype’s LINKAGE SECTION and PROCEDURE DIVISION header describe it.