Refined Printing Command Stream, also known as RPCS, is a vector-basedZenographics Zx-protocol comparison and overview printing/duplicating control protocol, designed for communication between Microsoft Windows PC clients, and several lines of Ricoh copiers. Drivers provided by Ricoh install the chosen copier to behave as a printer device.
The size-efficiency of the protocol is comparable to PCL6.
Drivers Ricoh offers RPCS based drivers for Windows, Mac OS and to some extent for Linux.
Linux Drivers for Linux are provided only on the Japanese website. Instead of Aficio they are called IPSiO. https://forum.manjaro.org/t/ricoh-original-geljet-rpcs-printer-drivers-aficio-ipsio-and-similar-sg-brands/19404
See also Ricoh Hong Kong PCL - Printer Command Language, a printer control protocol family designed by Hewlett-Packard
References
Further reading A tutorial about installing the Ricoh RPCS driver on Linux