Around in the 20th century until the 70s, especially in the 1940s and 50s.
Mostly used by and associated with gay men in big cities like London
A slang form which emerged due to the legal and social judgement and condemnation of homosexuality, and to therefore avoid being imprisoned.
Parts of Polari had been used in the 1700s and 1800s as a secret language the homeless, performers, sailors and ‘gypsies’ used