Forum:Achievements:New tracks

I've a question about the creation of new tack for the achievements extension: how can I delete a customized track? (Not simply deactivate, but completely delete it). And it's possible to create a track for a namespace, like "Template:" or "File:"? I tried to add the track for the category "Template" on my wiki, but it doesn't recognize the subcategory, so it's meaningless... that's why I want to remove it, and that's why I wish to know if there is another way to do that. Alternately I'll propose that as possible new feature.