The Universal Category System (UCS) is a set category list for the classification of sound effects. This provides a framework for consistent categorization of sound effects, offers uniformity in a filename structure, and eases the pain of maintaining your sound effects library.

UCS is a public domain initiative by Tim Nielsen, Justin Drury, Kai Paquin, among others, and supported by sound librarians, vendors, and users from around the globe. Learn more at universalcategorysystem.com.