Addon Rules?

FelixTheGreat

What exactly can addons do and not do? I'm curious about someone adding an addon (hehe unintentional alliteration) for things like improved graphics/better models for armor. What are the limitations to addons and how does Zenimax enforce these rules?
Thank you for your time in advance

Garkin

Addons can modify user interface (menus, unit frames...), they can't modify anything in the 3D world (such as textures or models).

And here are terms:
https://account.elderscrollsonline.com/add-on-terms