COBOL programs have access to almost all the interprocess communication methods discussed in this guide, including call-by-reference parameters, events and interrupts, port files, and libraries. The only interprocess communication method that does not apply to COBOL is the use of globally declared objects, because COBOL cannot initiate an internal procedure. For details about any of these interprocess communication methods, refer to Sections 13 through 20.

COBOL85 also supports ANSI-defined methods of interprogram communication. For the most part, ANSI interprogram communication simply defines the relationships between nested programs that are all executed as part of a single process. By contrast, the interprocess communication features of COBOL85 are enhancements that allow data to be exchanged between separate processes.