User blog comment:Guillejarque/Categorization models on RR3 Wiki pages/@comment-27416413-20160403002744/@comment-26249703-20160403212638

Not your fault, I'm not sure who added them there first, but that's often the case with categories. One person makes an edit of that nature, then a few other contributors jump on that train.

I have a format in my head and have tried to explain it before, but it perhaps wasn't clear enough. With a quick skim of this blog, I think Guille is on the right track.

As for NASCAR, I think some people added it like a LMP1 or Formula 1 category, rather than as the NASCAR Category (kind of like Amateur, Expert and so on). As I imagine it, (RR3) Categories would not include article pages, but (Wikia) categories, breaking down Career Series, Bonus Series, Vehicles, Manufacturers, meaning category tags would mostly be added to other categories, not article pages. That would make it easier to organise, but it's a future project, not current for me.