Been messing about, and on the american tis site there's something for getting calibration numbers of equipment in your car... 

https://tis2web.service.gm.com/tis2web/

Are they just the file numbers the Tech2 / MDI uses normally to download the software onto the car's modules? 

would they just be used to check if a module has the latest / correct software on it? 

or could those software codes be used somehow to tell the tech2 / MDI what software to load on if it wasnt letting you do