What is a normal surcharge?

Excuse me, could you please clarify what a normal surcharge entails? I'm trying to understand the context in which this term is used, especially in the realm of finance and cryptocurrency. Is it a fee that's typically charged for a specific service or transaction? And if so, are there any industry standards or guidelines that dictate what constitutes a 'normal' surcharge? I'm curious to know how this concept applies in practice and how it might impact consumers or businesses operating in the cryptocurrency space.