agencies use shelf files and end-tabbed folders to manage large filing systems. Variations on traditional shelf files, designed to offer increased capacity for a given floor area, include Rotary Storage systems. Specifications Within the United States, the primary standard for vertical filing cabinets is the Business and Institutional Furniture Manufacturer's Association (BIFMA) Standard X5.3. BIFMA used to maintain a separate Standard X5.2 for lateral filing cabinets, but that standard has been withdrawn. The standards provide requirements for cabinet stability, durability, and strength, among others. The General Services Administration (GSA) also maintains standards for vertical and lateral steel filing cabinets, A-A-3186 and A-A-3187 respectively. The GSA standards define two grades of filing cabinets, medium- and heavy-duty. They reference the BIFMA standard for the medium-duty cabinets, and provide additional performance requirements for the heavy-duty cabinets. The GSA is also responsible for maintaining the standards for filing cabinets and security containers for storing classified materials; more information on that subject may be found in the article on classified information in the United States. In the United Kingdom the dimensions and certain aspects of rigidity, construction, and safety are covered by BS 4438:1969 and BS EN 14073-2:2004. The safety standards revolve particularly against stability with drawers fully open. Interlocking mechanisms to prevent opening two drawers at once are not mandatory, but the employer's responsibility under the Health and Safety at Work Act makes them advisable. In other EU states the EN 14073-2:2004 harmonised standard will be endorsed by the relevant standards agency, such as DIN in Germany. In Australia filing cabinets should be to AS 5079 a modified version of ANSI BIFMA X5.2-1997. Filing outside the US Non-US firms offer filing cabinets that permit A4 paper to be used in addition to letter-size. Double file cabinets have drawers which can each accommodate two racks for folders side by side. Many European companies engineer filing systems that accommodate hanging folders only; there are no drawer bottoms. In the US, most file drawers still have bottoms in the drawers so materials of any sort can be stored. UK filing cabinets are slightly different from US in the width of the rails which support the suspension files, the US ones being narrower; the UK sizes are known as A4, foolscap and A3. Decline As some offices have tended towards paperless operation - i.e. storing more and more information on computers, rather than on paper - filing cabinets,