Yeah, I've been getting the hang of that as well. For the Text/HTML module, "edit" is pretty straightforward, and obvious. For the Forum module, "edit" means "can post", and for Gallery moule, "edit" means "can upload pictures (and edit descriptions, etc.)". There really isn't any other better name than "edit" that works across all module types. And, once you understand that "edit" means "can do more than just look at", it gets easier!