Topic summary
6P4C
Extracted from the Wikipedia article Modular connector.
6P
Modular plugs are described by the maximum number of physical contact positions and the actual number of contacts installed in these positions. The 6P2C, 6P4C, and 6P6C modular connectors are probably best known for their use as RJ11, RJ14, and RJ25 non-powered registered jacks, respectively (and 6P4C and 6P6C for powered RJ11 and RJ14, power being delivered on the outer pairs). These interfaces use the same six-position modular connector body but have different numbers of pins installed.