>My request is more basic though - what can I legally code there? For instance, I see "String" and "Integer". I'm looking for the details of:
>1) what's valid to code "As ........"

Any Fox data type, as well as any ProgID in the registry.

>2) when I would use each.

Use the Fox data types to write the data type to a type library. In addition, depending on the _vfp.languageoptions property value, output will be generated to the debug output window if you don't declare your variables.

If you're doing CreateObject() or NewO() for COM servers, then the AS will enable IntelliSense on the object.

In either case, it is not required, it is merely an aid to you as a developer, or to any dev who might use your COM server.