A family of plugs and sockets used with registered jack (RJ) twisted pair cables. They are defined by the number of positions on the connector that can hold a wire contact and the actual number of contacts. For example, a 6P2C connector means six positions and two contacts (two wires); however, they do not define the purpose of the wires. Common types are 4P4C, 6P6C, 6P4C, 6P2C and 8P8C.