Technicians and repairmen are often confronted by clueless customers who claim that the products they have bought are not working properly or not as advertised when, in fact, there is nothing wrong with the products and, therefore, the problem is with the user. In such cases, there is often no choice but to take the customer’s word for it.

As this can be somewhat annoying, technicians coined a derogatory term for it: equipment superior to operator. It means that the device or equipment is too advanced for the user to operate it correctly.

In simple terms, it means "user error."