I want to know what Kakashi's name was in the Anbu because Yamato's real name is Tenzo which is very different.
I am pretty sure Kakashi's code name was never revealed or touched upon as I've seen pretty much the entire series.
Fanfics do have names such as Hound but nothing shows that I was ever mentioned in the anime or manga or even any light novel.
Kishimoto Sensei might've answered a question in an interview (highly unlikely though) but I haven't seen any evidence for that yet too
Also I read on this Yahoo Answer that names were usually changed after the missions but I couldn't find anything supporting this assertion.