Military insignia and epaulet tattoos are often used to signify criminal accomplishments or some other aspect of a prisoner's history. Skulls generally designate murderers. The crest in the drawing above refers to the White Guard--troops who fought against the Red Army in the Russian Revolution--and can mean that a prisoner was a high ranking criminal or had some special status as a criminal before their incarceration. The epaulet in the drawing below indicates that a prisoner has done time in solitary confinement. Nazi imagery is very common. An SS insignia can indicate that a prisoner is respected for never having confessed to anything.