Help:System messages

System messages, also called MediaWiki messages, provide a means for customizing the interface of a wiki. Each system message has a predefined value that can be overridden by editing the appropriate page in the MediaWiki namespace.

Background
When MediaWiki was first coded, the need for the interface to be heavily customizable quickly became apparent. Many communities wanted to tweak certain words to incorporate wiki-specific terms, for example using the term "Scribble" versus "Edit" on creative writing communities. Foreign language wikis needed a way to quickly translate terms from English into their native language.

The solution was system messages. Almost every word you see as part of the interface - from the "Edit" button to the message welcoming users to chat - is customizable.

When an extension or feature is introduced to MediaWiki, Fandom staff give each piece of its interface a pre-defined English value that can be overridden by editing the local message in the MediaWiki namespace. A list of all system messages on your community is available at Special:AllMessages.

While the messages are there for the purpose of customization, please keep in mind that it is not always wise to tweak these messages. The default value is there because it is considered the most universally understandable terminology. So while "edit" may make more sense to say "revise", "scribble", "tweak" or something to one community, "edit" in general is considered the most straightforward wording that invokes to the average user what the edit button will actually do when clicked.

Step by step
As the messages are stored in the MediaWiki namespace, only admins of a community have the necessary permissions to be able to make changes to the system messages.

'''However, for security reasons, not all MediaWiki messages are freely editable. A whitelist of editable messages has been created, which is listed on Help:System messages/whitelist.''' Messages not listed there require a request to Fandom Staff for editing.

Using Special:AllMessages
Tip: Pay very careful attention to anything with a "$" in the message. This designates a system variable that will fill in with extra text when the message is actually being invoked. It is best to seek outside help from the Community Central Forums if you are unclear what these variables represent. Tip: Clear your browser cache (Ctrl + F5) if you do not immediately see the change.
 * 1) Go to Special:AllMessages and select the "all" radio button. Search the default text and locate the message you would like to change. Click the message in question.
 * 2) If the message has never been edited before, you will see the editor prefill with the default message value. This will help confirm you are editing the correct message.
 * 3) Edit the page just like a normal page, putting in the message text.
 * 1) Save the message and verify the message has properly changed.

Using the special language code trick
In many cases you can use a special 'language' code to find out a message name more quickly. This can be done by appending ?uselang=qqx to the URL (see this page as an example). All the messages on that page will then be replaced by their message keys, which are the names of the pages in the MediaWiki namespace.

Notable system messages

 * MediaWiki:Common.css - controls custom community CSS
 * MediaWiki:Common.js - Controls custom community JavaScript
 * MediaWiki:Mainpage - Controls the landing page when a user goes directly to the community's main URL in their address bar (such as 'community.wikia.com')
 * MediaWiki:Licenses - Defines the options users see for image copyright status when uploading an image
 * MediaWiki:Edit - "Edit" by default, this message controls the text one clicks when they wish to edit a page
 * MediaWiki:Newmessageslink - Customizes what the new messages bubble says
 * MediaWiki:Newarticletext - This is the message that you get when you follow a link to a page that doesn't exist yet

Further help and feedback
pt:Ajuda:Mensagens do sistema de:Hilfe:Systemnachricht es:Ayuda:Mensajes del sistema fi:Ohje:Järjestelmäviestit fr:Aide:Messages système it:Aiuto:Messaggi di sistema ja:ヘルプ:システムメッセージ nl:Help:Systeemberichten pl:Pomoc:Komunikaty MediaWiki vi:Trợ giúp:Thông điệp hệ thống zh:Help:系統訊息 ru:Справка:Системные_сообщения