We had a job on which the translator argued with the client about the translation of the word "scanner". The argument lasted for days, and the translator gave many reasons for her choice of terminology, referencing dictionaries and her own experience. But in the end, the main argument was the client stating that in their business, the end user always calls scanners this way, and it doesn't matter what the dictionaries say—the client has a business and in their business scanners are called scanners, nothing else. All else is unimportant.