People often spell the names in such a way that each letter making up the name

People often spell the names in such a way that each letter making up the name being spelled is used to make up some commonly heard word which start with it to facilitate the listener. I have heard people using two different ways of doing it and I don't know which one is correct.

1: My name is Putin, P as in pink, U as in umbrella,....
2: My name is Putin, P for pink, U for umbrella,....