I’m a bit confused about these. Apparently they are for taxis, but I have seen (yellow) taxis with black plates.
My main curiosity though are the unmarked cars with the red letter/number plates. I’ve seen car types running the gamut of brand and age with these, from Toyota to Audi and maybe even some Mercedes. Are they private taxis or do “company cars” given out also carry these plates - or is it something else entirely?