'Satisfied by' Linking

Hi
I've created 'Satisfies by' links in a module. In some instance the link has a superscript saying 'In this module only', in other 'In all modules' and in others, no superscript at all. I'm confused about how this has happened, and what exactly it means. I've also noticed that it seems to affect which links are included when I create an export.
Thanks
Mark