The unwritten laws and rules of Electronics

I do. Vehicle key and house key in each set. I forgot, my truck keys have not only the house key and my work desk key, but also a USB flash "key". So that's four. ;-)

What uniform?

Don't parking valets have some sort of uniform to match the hotel, restaurant, or whatever? Surely you identify them in /some/ way, rather than just passing your keys to whoever stands beside your car door with his hand out.

(We don't have parking valets on this side of the pond, so I have no experience with them.)

They don't always wear any sort of uniform. It depends quite a bit. There is usually a supervisor, who may wear a uniform, but the drivers themselves usually don't, IME. Usually, the valets aren't employees of the establishment, rather a service. The valets at the hospital (I spend too much time at) don't wear nurses' uniforms. ;-)

That's surprising. They're most used here where parking is a premium and may not even be available on-premises. I would think that would be a pretty common problem in most large cities.