The moon is a category II body, with the only requirement being potential contamination must be documented. This is an area that has been covered by international treaties since the late 60s.
> Unrestricted Category V: “Earth-return missions from bodies deemed by scientific opinion to have no indigenous life forms.”
In their ‘wisdom’, they decided to use Roman numerals I through V for both.
Missions to the moon fall in mission category II, but the moon itself falls in target category V (more precisely unrestricted category V)