Provenance and declarations
What you are claiming when you submit, the five categories, and which one makes an entry ineligible.
Every submission declares where the model came from. This is the load-bearing statement on the whole platform: it decides what the leaderboard is allowed to say about who built what.
Why reselling is refused
If an unchanged model can be entered under a reseller's name, the leaderboard ranks somebody else's model under your brand, and a reader comparing two entries is comparing the same model twice. That is not a policy about fairness, it is about whether the board means anything.
Naming the base model
Every declaration except the first requires you to name what it is built on, and that name is shown publicly next to your result. A fine-tune that beats its base is a real achievement and the comparison is the interesting part.