ISO2002MF 

Conventions for Program-prototype-names

Program-prototype-names referenced within a source element must be either the program-name of a containing program definition or a program-prototype-name declared in the Repository paragraph

If a program prototype is specified in a Repository paragraph and the program prototype declaring the same program-prototype-name is also specified within the same compilation group, the program prototype specification is used and the information in the external repository for this prototype is ignored.