You probably meant mostly "Urks" from Soviet gulags.
I just wanted to say that the prison caste system predates the Soviet Union and in Poland it was strongly influenced by Jewish inmates (who were a large part of the prison population in prewar Poland and earlier). So in the Polish prison subculture there are generally 3 tiers: 1st tier is/was "git" people/gitowcy (git comes from the Yiddish pronunciation of German "gut"), 2nd is frajer(zy) -losers/suckers, so the general jail population who are not Git people (frajer in Yiddish originally meant a non-religious male) and the 3rd tier - "cwele/cwere" (possibly from German "Schwellen" - railroad tie or "Schwul"-homosexual male, a phonetic mutation thru Yiddish is possible) are the lowest of the low - child rapists, mother-killers, snitches, passive homosexuals, those who break the prison moral code etc.. They are regularly abused both sexually and physically by other inmates, almost in a ritualistic manner. To sum things up - Polish prison culture has a lot of Jewish culture in it - words like cynkwajs (a form of facial prison tatoo), dintojra (prison kangaroo court, orginally meant rabbinic court in the diaspora), etc., same with rituals and taboos. Prisoners are mostly unaware of it.
Thank you for coming to my TED Talk. Next time I can explain the Vory v zakonie (thieves in law) subculture of the Russian penal system.
Edit. - a few typos.