A cover (102, 202, 302, 402, 502, 602, 702, 802, 902, 1002, 1102, 1202, 1302) for a document file (100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300) is disclosed as including a front cover (104, 304, 404, 704, 804, 904, 1004, 1204, 1304) and a back cover (106, 406, 706, 906, 1006, 1206, 1306) joined with each other, in which the back cover is engageable with a paper-retaining mechanism (116, 316, 416, 616, 716, 916, 1016, 1216, 1316) with at least two openable rings (122, 322, 422, 622, 922, 1022, 1222, 1322), in which the front and back covers are movable relative to each other to a closed configuration in which the front and back covers generally face each other, and the front cover includes hooks (1120, 220, 320, 420, 620, 720, 1020, 1120) or a wire (1366) which, when the covers are in the closed configuration, extend from the front cover towards the back cover for releasable engagement with the rings. A document file (100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300) with such a cover is also disclosed.