Assembler programs usually have file extensions of .MLC or .ASM and can be included into any Enterprise Developer project.
Assembler modules with EXEC CICS statements in them are usually identified with the file extension .CAP. When these modules are added to your project you can assemble and link them into either data tables with the extension .MOD, or as executable modules with the extension .390.
As a result while assembler modules can be linked to make assembler to assembler calls static or dynamic, all Assembler to COBOL or COBOL to assembler calls must be dynamic.