8.3 Using Alternatives to Include Files

If your project uses only two modules (or if it is written with a version of MASM prior to 6.0), you may want to continue using PUBLIC in the defining module and EXTERN in the accessing module, and not create an include file for the project. The EXTERN directive can be used in an include file, but the include file containing EXTERN cannot be added to the module that contains the corresponding PUBLIC directive for that symbol. This section assumes that you are not using include files.