Use /DLL to identify the output file as a dynamic link library (.DLL file). The object files should be compiled with the PL/I option DLLINIT.
If you specify /DLL with /EXEC, only the last specified of the options takes effect.
If you do not specify /DLL, or any of the other options, then by default the linker produces an .EXE file (/EXEC).
Default: /EXECUTABLE
Abbreviation: /EXEC