Registration of a guidance package (either by running the GAT Register recipe or installing from an MSI) is what will properly inspect the templates contained in the Solutions, Projects and Items folder of your guidance package and will generate supporting files and updates to the registry. The process of what this gets done is rather extensive and complicated because a lot of stuff happens behind the scenes.
If you could shed some light on what are you after I could try to provide some specific info,
thanks,
-Victor.