MediaWiki:Clearyourcache

 '''Note: You may have to bypass your browser’s cache to see the changes. In addition, after saving a sitewide CSS file such as MediaWiki:Common.css, it will take 5-10 minutes before the changes take effect, even if you clear your cache.'''
 * Mozilla / Firefox / Safari: hold Shift while clicking Reload, or press either Ctrl-F5 or Ctrl-R (Command-R on a Macintosh);
 * Konqueror and Chrome: click Reload or press F5;
 * Opera: clear the cache in Tools → Preferences;
 * Internet Explorer: hold Ctrl while clicking Refresh, or press Ctrl-F5.