Game description file used by SimCity 4, a city-building and simulation game; describes game properties such as the location and type of buildings and props; also specifies how people in the city interact with the buildings.
SC4DESC files are often used for creating custom properties for a lot, which is stored in an .SC4LOT file. SC4DESC files are created using the Plug-in Manager program, which is part of Electronic Arts' Building Architect Tool suite. They may also be edited with the SC4Tool and iLives Reader.