404. That’s an error.
The requested URL /bookmarks/mark?op=edit&bkmk=http://twiki.org/cgi-bin/view/Plugins/FirefoxExtensionAddOnDev&title=Firefox%20Extension%20Add%20On%20Dev&annotation=Firefox%20Extension%20Add%20On%20Dev%20in%20Plugins%20web%20on%20twiki.org
was not found on this server. That’s all we know.