It provides collapsible boxes: when closed only the title of the box is visible; when opened the complete box becomes visible. A open/close icon (+) will be shown at the right edge of the box, indicating the status of the box. E.g. Table of contents plugin renders the toc by default inside a collapsible box.
-- DF, Nov 05, Jul 06, added to JSPWiki since v2.5.80.
The first !, !! or !!! becomes the title of the collapsebox. Use the style %%collapsebox-closed to close the box by default.
%%collapsebox ! Title of the box Here is the body of the box * item 1 * item 2 /%