"Petukhi" ("the Roosters")
These are the lowest layer of inmates, something like the pariahs. They are the subject of constant humiliating acts (including anal rape) from other inmates.
They are not allowed to touch the "normal" inmates or to share any items with them, and occupy the worst places in the prison cell. Contacting a "petukh" is "zapadlo" and can sometimes even lead the other person to be declared a "petuh" - usually by beating and knocking under the bed ("pod shkonku").
Sometimes, a person can become a "petukh" due to the offense for which he is imprisoned. Sexual offenses, especially against minors or women completely unknown to the offender (street rapes), are an example (rape of women after being her guest and drinking with her is not considered a humiliating deed). Homosexual acts were illegal from 1933 to 1993, and all those jailed for this were automatically considered petukhi.
The status of "petukh" is lifelong and cannot be cancelled. A "petukh" is obliged to warn everybody on his status (the standard formula - "I have problems in this life") in any new prison/camp he is relocated to, and even in his possible next imprisonment after serving the current punishment and being released. Otherwise, it is considered that he polluted ("zashkvaril") the normal people who had any contact with him while being unaware of his "petukh" status. This can lead to a severe beating or even murder.
Read more about this topic: Thief In Law