This secret language allowed gay men to communicate when homosexuality was illegal.

Efforts to preserve the cryptolect have seen mixed success. Kevin Whipple - Culture Trip
If you were a gay man living in England in the mid-20th century, you might greet your friends with “how bona to varda your dolly old eek”. This secret language, or cryptolect, served to help those in the gay community weed out who was “in the life” and who was not.