Also, the name for a third party add-on to a BBS, most commonly a game, but sometimes a statistics generator, an offline mail tool, or others. Doors are independent programs called by the bbs program, and take information from the BBS in the form of a drop file, a text file with information such as username, access restrictions, time left online, etc., in a specific format. After the program is run, control and the user are returned to the BBS. Many bbses have their own format of drop file; the most commonly used are DOOR.SYS, which stems from the GAP bbs software, and DORINFO or DORINFO1 (from RBBS?). While some door coders made an effort to support as many drop file formats as possible, more recent BBS software packages have instead opted to be able to generate many different drop file formats to fit the door. Popular doors include LORD, Trade Wars 2002, BRE, The Pit, Bluewave.