I've never really thought about how it's done on the older generation parts. On the newest it's etched by laser. We had a generation where it was stick on barcode and that was the worst.
Well, it looks to be battery powered with illuminated push button controls. Looking like it can be clipped into a base unit or detached and used remotely.
So, my guess would be the winch and bed control for a vehicle recovery vehicle.
Cursory search from the model number turned up nothing. My guesses are judging from the LEDs, it could be a mini-camera lighting module, fancy flashlight or a drone lighting accessory.
I'm not sure! If I had to hazard a guess, it would be that the board was assembled on Jan 2019. Or I guess 19th January, technically (although this seems less likely, it makes more sense to indicate the year I think).
It could also be the batch number or assembly line number, but it seems more likely to be a date.
The board version (V2.2) and some form of product identifier (DK001-D) already seem to be there, so those are ruled out.