 Membership in a qaum is inherited by birth.Barth identifies the origin of the stratification from the historical segregation between "pak" (pure) and "paleed" (impure)—defined by the family's social or religious status, occupation and involvement in sexual crimes.Originally, "Paleed/Paleet" qaum included people running or working at brothels, prostitution service providers or professional courtesan/dancers ("Tawaif") and musicians.