Dymo LetraTag QX50 Easter Egg - Hidden Features

Hold down one of these keys during power-up and watch the result printed on tape.
1. Any of the arrow keys: Hexadecimal math (why did they put this in there?)
2. DEL key: Firmware version
3. I key: Production codes.
4. O key: Language-specific character maps (warning: this uses up almost an entire roll of tape!)
5. P key: Internal character set