Manual:Using custom namespaces

In addition to the built-in namespaces, it is possible to add custom namespaces to a MediaWiki installation, to further separate content and allow more logical organization.

Custom namespaces are simple to manage using the  configuration directive. It is also possible to define alias names for custom (and also predefined) namespaces, using the  configuration directive.

Creating a custom namespace
You add additional namespaces to the $wgExtraNamespaces global variable. Manipulation of this variable must be completed before completion of MediaWiki initialization; for instance it cannot be manipulated in a extension post initialization hook. As an example of simple custom namespace creation, one can add an appropriate line to, e.g.

Note the use of the constant 500 in defining the namespace. All namespaces require a numerical index; for custom namespaces, the indices start at 100. In choosing such an index, you may want to avoid any that is listed in extension namespace registration as being used by an extension, since you might want to install that extension later. It is recommended that you define a discussion namespace with each custom namespace, so the declaration above might be expanded to:
 * even namespace index denotes a subject namespace.
 * odd index denotes a discussion ("talk") namespace.

With this declaration, if a page is moved to the Foo namespace, numbered 500, you will be prompted to move the associated talk page. If you choose to do so, MediaWiki will place the page in the namespace numbered 501.

If you need to refer to the ID of your namespace later on in the configuration, for example for $wgNamespaceProtection, $wgNamespacesWithSubpages or an extension like Lockdown, it is recommended that you define constants for your namespace IDs (only letters, numbers and underscores allowed):


 * Do not use spaces

Use underscores instead of spaces in namespace names. 'My Namespace' is an invalid name; use 'My_Namespace' instead.

In extensions
Extensions often add their own namespaces, such as the Flow extension's "Topic:" namespace. An extension can unconditionally add to $wgExtraNamespaces as described above, or if its namespace registration is conditional (for example EventLogging] only defines its "Schema" namespace on the wiki where it stores schemas), then it can respond to the [[Manual:Hooks/CanonicalNamespaces|CanonicalNamespaces hook.

Content namespaces
When building the site statistics page (see Special:Statistics), MediaWiki uses values stored in the database to calculate certain totals. One particular total is the "number of articles" or "number of content pages" figure.

For a page to be considered an article, or proper content, it must:


 * Be in the main namespace, or a defined content namespace
 * Not be a redirect  page
 * Contain at least one internal link

When creating custom namespaces to hold additional content, it is a good idea to indicate this in the configuration. This is done via the $wgContentNamespaces configuration directive.

To extend the example above, one might add the following to :


 * or


 * for more than one namespace:

MediaWiki will now consider pages in the "Foo" namespace to be articles, if they meet the remaining criteria, and will include them when updating the site statistics counters.

Running maintenance scripts

 * When adjusting the value of, it is a good idea to run either the   or   script to update the internal statistics cache (see: Manual:Maintenance scripts).

Why you would want a custom namespace
There are several reasons on why you would want this:


 * A custom namespace can be used to hold content that should not be shown on the search results page, for example pages that are used only for transclusion.
 * Certain namespace require additional privilege(s), i.e. for reading or editing
 * You want certain namespace not to be subjected to certain limitation or default settings ($wgNoFollowNsExceptions for example)
 * A uniform prefix for specific content(s), which is searchable for that namespace only
 * If you're an MW developer, sometimes you need to have a custom namespace for your extension(s)

Dealing with existing pages
When storing page records, MediaWiki uses a namespace's numerical index, along with the remaining title text. Thus, when a page is created in a namespace that doesn't exist, e.g. "Bar:Some page", it is treated as being in the main namespace.

This can cause problems if adding a custom namespace definition for "Bar" at a later date, as MediaWiki will look for a page indexed via the proper namespace, but won't be able to find it, thus making the content inaccessible.

To correct this problem, there are three main approaches.

Move conflicting pages
If the number of pages affected is small (e.g. "Bar" held five pages created before the namespace was defined in the site configuration), then the following approach might be suitable:


 * 1) Comment out the namespace definition in the configuration file
 * 2) Access each affected page, and move it out of the pseudo-namespace, e.g. move "Bar:Some page" to "Bar2:Some page"
 * 3) Un-comment the namespace definition
 * 4) Move the affected pages back into the new namespace

Use a maintenance script
Within the maintenance directory, there is a maintenance script which performs the above operation more effectively for a large number of pages; NamespaceDupes.php. It is simple to use, but as with all MediaWiki maintenance scripts, consult the available usage information first (use ) as an option.

Use a database query
To move all pages "Bar:Some page" into namespace 500, make the following database query: To handle discussion pages:

Removing custom namespaces
The problem addressed above also occurs when a custom namespace definition is removed; MediaWiki is no longer aware of the numerical index for the namespace, and attempts to search the main namespace for the desired pages, leading to inaccessible content. This is a rare occurrence, since most sites will not need namespaces removed, but it is a problem. (See mailing list discussion).

Avoid namespace conflicts
In order for you to avoid namespace conflicts [e. g. your namespace has the same number as a namespace defined by an extension, the extension namespace list shows you which numbers to avoid to prevent conflicts.

Defining $wgNamespacesToBeSearchedDefault, $wgNamespacesWithSubpages, $wgContentNamespaces or $wgNamespaceAliases for an ID not associated to any existing namespace in $wgExtraNamespaces doesn't break the wiki; MediaWiki gracefully ignores such configurations.

Styling namespaces (e.g. Background)
To set the background color of pages in the specified namespace, add following code to your common.css: where "500" is your namespace index, #f3f3ff is the namespace background color.