Excuse me, what does whisky hotel mean?

The White House. In the NATO radio code, Whisky Hotel = WH = White House. For example, "We are Oscar Mike" means "We are moving forward". You don't even know what it means before (the original meaning is probably "we won the Oscar, Mike", but the real meaning is "we are moving forward"). I wonder what the purpose is. Maybe it was used to prevent eavesdropping in the war.