Ahoi,

So there are various forms oc groups like the mafias use to communicate.The ndrangheta in italy use(d) Baccagghju and recently i heard that some groups used to adopt some kind of whistling "language"(there are real whistling languages,but i think that this one has just limited vovabulary and grammar) for their "talks" on the telephone.
In germany Ringvereine use drotwelsch until the 60s and other groups in europe also have and had their special forms of communication(and i dont mean pizzini).
have there ever been similar forms in the USA?
any ideas?