What is an Overmax fee?

Excuse me, could you please clarify what an Overmax fee is? I've come across this term in the context of cryptocurrency transactions, but I'm not entirely sure what it entails. Is it a type of penalty or surcharge that's imposed in certain situations? If so, could you elaborate on the specific circumstances that might lead to an Overmax fee being charged? Additionally, how does this fee compare to other types of fees that are commonly associated with cryptocurrency transactions? Thank you for your time and assistance.