Help:System message

A system message is a snippet of plain text, wiki text, CSS or Javascript that can be used to customize the behavior of MediaWiki and its appearance for each language and locale.

Special:Allmessages
Interface and other system messages can be customized by editing pages listed on Special:Allmessages. Editing interface messages is typically straightforward, just like editing a normal wiki page.

The Special:Allmessages table contains two columns: the linked interface name, and the text. The text is horizontally split to show the default text above, and the customized text below. When a custom message does not exist, only the default will be shown. To customize a message, click the upper link in the left column (the name of the message). This link is red if the default text is in use, because the edit page is empty.

The lower links in the left column cells lead to the discussion pages for that message.

Built-in system messages
For a complete list of documented interface and system messages, please see Category:Interface messages. These pages document how each message is used by MediaWiki, variables available, parameters used, limitations, et cetera.

For convenience, links to some of the more commonly used messages are listed below:

Styles and JavaScript

 * JavaScript
 * Stylesheets
 * Common.css
 * Common.js
 * Monobook.css
 * Monobook.js

Visible messages

 * 1movedto2
 * 1movedto2 redir
 * Blockedtext
 * Copyrightwarning
 * Movepage-moved
 * Protectedpagetext
 * Searcharticle
 * Searchbutton
 * Sidebar
 * Sitenotice

Hidden data

 * Disambiguationspage
 * Sitenotice id

Creating new messages
Extensions can (and should) define system messages for any text displayed in the user interface. This assists in the localization of those messages. For an example of how to do this, please see Manual:Special pages.