RDC is the file extension associated with an integrated geographic information system (GIS) called Idrisi. RDC files are used to store metadata about the content of RST files. They may also store information about the location of REF and SMP files. RDC description files were previously given the DOC extension, but these were changed to avoid confusion with another popular format.

Idrisi Taiga is a tool published by Clark Labs, but its original author is J. Ronald Eastman.