Abstract: A conversion tab assembly for conversion of a top-index file to a side-index file, consisting of a base sheet having a tab portion at one end of the sheet, an adhesive to mount the tab assembly to the top-index file, the tab being adjacent to one side edge of the file, and the primary sheet having a strength and stiffness to enable the side-index file to be displaced using the tab, and a flap foldable along one border of the base sheet to permit the sandwiching of a panel of the file between the base sheet and the flap securely using bonding materials, thereby reinforcing the file.