Actual arguments are the text given in the macro call after the name of the macro.
The number of actual arguments in the macro call can be less than or equal to the number of formal arguments in the macro definition. If the number of actual arguments is greater than the number of formal arguments, the assembler displays an error message. Formal and actual arguments normally maintain a strict positional relationship. That is, the first actual argument in a macro call replaces all occurrences of the first formal argument in the macro definition. This strict positional relationship can be overridden by using keyword arguments.