Acceptable use policy (AUP)
The list of things you may not do with a service, even when you're paying for it.
Where terms of service govern the whole customer relationship, an AUP is narrower: spam, intrusion, illegal content, crypto mining on the free tier. The most historically consequential one belonged to NSFNET, which banned commercial traffic on the US backbone and thereby forced the creation of private exchange points such as CIX before the network was privatised in 1995.
Cloud providers rarely invoke their AUPs, but when they do it shows. AWS cut off Parler in January 2021, citing its AUP. The idea has since migrated into licences as well: the Llama licence and the OpenRAIL family attach an AUP to the model weights, so usage restrictions that once applied only to a service now apply to a file sitting on your own disk.