Hello! We use British English for our keys and definitely avoid spaces in the key. Incidentally, the key ref:FR:NAF has already been used 41,047 times. In my opinion, it is questionable whether a classification of the number of employees should be collected at all. In the school environment, there is information on the number of pupils and teachers, but here too, there are only numbers and no classifications. These can be added via the reference number if required.
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