Proteus is a prison planetoid, where criminals (and their descendents) serve their time making munitions and ambrosa. When the munitions ran out, the prisoners continue to create ambrosa, believing that they were helping the Colonies in the war effort against the Cylons.
Prisoners are named for their crime (Embezzler, Forger, Adulteress, Assault) as well as a number for identification purposes. Descendents of the criminals inherit the name/crime of their parents but increment the number.
The prisoners who originally were sentenced to the prison were known as the Original Sinner. The prison is overseen by the enforcers, who are descendents of the staff who were originally in charge of overseeing the Original Sinners (The Long Patrol).