"Seccy" was the slang term used for freed ex-slaves and their descendants, who formed the legally second-class citizens of Mesa. Sometimes, calls were made to expel all seccies from the Mesa System. However, by the 20th Century PD, they had become an integral part of Mesa's social and economic structure and provided a number of useful functions for the planet's freeborn citizens. Mesan security kept a close eye on the seccies, even though seccy society was socially intricate, often shadowy, and intermixed with that of Mesa's freeborn citizens.