GIS metadata file created by IDRISI Taiga, a program used for imaging spatial data; saves descriptive information about the raster image stored in a .RST file; also can store a reference to the .REF geographical reference file for the image, as well as an .SMP palette file.

NOTE: IDRIS raster documentation files formerly used the ".doc" extension. However, Clark Labs changed the extension to ".rdc" so that IDRIS raster image file types would not be confused with other file types.