My friend and I have known each other for many years. We are able to hold conversations in which we abbreviate words, use some words which are only known in our immediate locality and use hand signals ( a bit like racing pundit John McCririck who, funnily enough, calls his wife Booby). We find such conversations are extremely useful in pubs when we do not want eavesdroppers to learn our business. They notice the hand signals and some listen to us for a short period but usually walk away to talk to someone else. We are perfectly satisfied that we are booby.