Is there a technical convention (maybe unofficial) as to which side to mount upwards ? I imagine there could be such a guideline, because the marking could rub off or users might have impaired vision.
I know this might attract opinions, but those should be shared here. I am asking from the device manufacturers' perspective (the one who builds the switch into their chassis), specifically if there is a safety norm or similar that mandates one particular orientation.
I admit that I have done it as I saw fit in the past, with no-one complaining. But I have doubts that this is universal.