Abstract: An identification system for file folders having a front panel and a rear panel with a fold therebetween forming a pocket into which paper may be placed includes a rail disposed in the vicinity of a top edge of the rear panel of the file folder and extending across a width thereof, and a tab, including a pocket for inserting a file identifier, supported in frictional engagement with the rail for sliding motion on the rail across the width of the file folder. This permits easy adjustment of tabs as file folders are inserted and removed.