One of the wireless numeric keypads I’ve been using with the streaming radio players developed some intermittent key switch failures resisting all the usual blandishments. Eventually it hard-failed, but I was unwilling to scrap the tediously printed keycap labels:

Hard to believe, but I’ve been using the white keypad for plain old numeric entry with the keypad-less Kinesis Freestyle 2 keyboard.
I swapped the Frankenpad + receiver to the least-conspicuous streamer and, someday, I’ll update all the labels on all the keypads to match the current streams. Until then, the white keycaps shall remain in the same bag as the defunct black keypad, tucked into the Big Box o’ USB mice & suchlike.