"Note: Although RJ45 is the common name for the UTP Ethernet connector, this is a misnomer. The correct name for the connector is 8P8C, which indicates an 8-pin, 8-conductor connector. The actual RJ45S connector is an eight-position connector but is used for telephone rather than computer data. An RJ45S jack has a slightly different shape than the connector used for Ethernet, and it includes a cutout on one side to prevent unkeyed connectors from being inserted into it."
I don't think I have ever seen a reference to 8P8C, at least not in the port name. Maybe it's what the cable connector is called but the jack is an RJ45?