Can you show any specific examples? Offhand it sounds like maybe it's the revision (i.e., BL revision PCVs), but I think some context might help. There's all sorts of deep lore mfers on here know
The first place that comes to mind is Kempers used parts (kempers.de). Here is what their car / parts selection menu looks like:
i don't even see GTI in that list so i am guessing it is one of those model codes? Maybe? What is Variant?
i someone somewhere say 5G was the Mk7 and 5G1 was the Mk7.5, but i have seen other places that contradict that.
Why Kempers? My eight year old dreams of having various parts from our car (his sole reason for wanting to do mods on the car i suspect so that he can have the original parts). i look at places like that daydreaming of picking him up an EA888 to take apart. Yes, that's what he asks for his birthday, Christmas, etc. He wants to take apart our engine. Or a VR6. And then he will likely decorate his wall with all the parts.