GeezerVison

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 $wgExtraNamespaces configuration directive. It is also possible to define alias names for custom (and also predefined) namespaces, using the $wgNamespaceAliases configuration directive. Some extensions make it easy for you to create custom namespaces. Examples include NamespaceManager and BlueSpiceNamespaceManager .

You register additional namespaces by adding them to the $wgExtraNamespaces global variable to your "LocalSettings.php" file. All namespaces require a unique numerical index in this array. As an example of simple custom namespace creation, adding the following lines to the "LocalSettings.php" file defines a "Foo" namespace 3000 and its associated "Foo_talk" namespace. Note that having a talk namespace associated with your custom namespace is currently a hard requirement.

// Define constants for my additional namespaces.
define("NS_FOO", 3000); // This MUST be even.
define("NS_FOO_TALK", 3001); // This MUST be the following odd integer.

// Add namespaces.
$wgExtraNamespaces[NS_FOO] = "Foo";
$wgExtraNamespaces[NS_FOO_TALK] = "Foo_talk"; // Note underscores in the namespace name.

Pick an unused number

As a convention, the namespaces numbered 100-199 are reserved for site-specific namespaces, although there are some extensions that don't follow this convention. Extension writers use higher numbers, up to 32767. When choosing your index, you should avoid any number already in Extension default namespaces , since you might want to install that extension later. Numbers from 3000 to 4999 are reserved for system administrators to define their custom namespaces. (Also, you’ll want to avoid any namespace name that’s already in Extension default namespaces.)

Even then odd

Note the namespace array index is 3000 in the above example.

• an even namespace index denotes a subject namespace.
• the odd index immediately following that number denotes its associated discussion ("talk") namespace

Create the talk namespace too

You typically create a discussion "Talk" namespace along with each custom namespace. With this example, if you move a page into the "Foo" namespace, you will be prompted to move its associated talk page, if any, and if you choose to do so, MediaWiki will place the talk page in "Foo talk".

No spaces

Use underscores instead of spaces when registering namespace names. "My Namespace" is invalid here; use "My_Namespace" instead.

No hyphens

The uppercase part does not permit hyphens but they can still be safely added to the prefix title. Example:

$wgExtraNamespaces[NS_FOOFOO] = "Foo-Foo";

Name the numbers you pick

The example defines constants for the namespace IDs, so that you can refer to these namespaces later on in the configuration, for example in $wgNamespaceProtection , $wgNamespacesWithSubpages , or $wgExtraGenderNamespaces .

You could go on to configure additional settings for your new namespace.

$wgNamespaceProtection[NS_FOO] = [ 'editfoo' ]; // permission "editfoo" required to edit the foo namespace
$wgNamespacesWithSubpages[NS_FOO] = true;            // subpages enabled for the foo namespace
$wgGroupPermissions['sysop']['editfoo'] = true;      // permission "editfoo" granted to users in the "sysop" group

Do it early

Manipulation of $wgExtraNamespaces must be completed during MediaWiki initialization, i.e. in case an extension etc. should work with the newly created custom namespace, make sure that you define and name them prior to invoking the respective extension. For instance it cannot be manipulated in a post-initialization hook like $wgExtensionFunctions .

Watch out for collisions with URL protocols

MediaWiki's linking code knows about a number of URL protocols, defined in the $wgUrlProtocols variable. If your namespace name is identical to one of these protocols, you're going to have trouble creating [[wikilinks]] to pages in your custom namespace. This most commonly arises when someone tries to create a "News" namespace, because news: is a URL protocol for NNTP newsgroups.

To avoid this issue, you can deregister the relevant URL protocol by adding the following code to the "LocalSettings.php" file (replacing news by the lowercased name of the protocol you wish to remove):

$wgUrlProtocols = array_diff( $wgUrlProtocols, array( 'news:' ) );

Extensions often add their own namespaces, such as the Flow extension's "Topic" namespace. The extension.json registration system has a namespaces key for an extension to list its namespaces. From the Gadgets extension:

"namespaces": [
		{
			"id": 2300,
			"constant": "NS_GADGET",
			"name": "Gadget",
			"protection": "gadgets-edit"
		},
		{
			"id": 2301,
			"constant": "NS_GADGET_TALK",
			"name": "Gadget_talk"
		},
]

You can also set other namespace-related settings here, such as whether it should be a content namespace or not; see Manual:Extension.json/Schema for the available properties.

If namespace registration is conditional (for example EventLogging only defines its "Schema" namespace on the wiki where it stores schemas), the extension should add "conditional": true to the namespace definition in extension.json, and also register a handler for the CanonicalNamespaces hook there which decides whether to register the namespace or not. The hook handler should only change the $namespaces with which it is called; all other settings of the namespace should still be registered in the extension.json. If those settings should also be dynamic, do not change $wgContentNamespaces , $wgNamespaceContentModels etc. in the CanonicalNamespaces hook handler (it will have no effect – T288819); instead, you will have to set them earlier, such as in a callback (not in $wgExtensionFunctions ).

Note that adding an extension to LocalSettings.php does not necessarily make relevant namespace constants available as globals for other extensions.

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, as configured by $wgArticleCountMethod .

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 the "LocalSettings.php" file:

$wgContentNamespaces[] = 3000;

or

$wgContentNamespaces[] = NS_FOO;

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.

When adjusting the value of configuration parameter $wgContentNamespaces, it is a good idea to run either the "path/to/maintenance/updateArticleCount.php or "path/to/maintenance/initSiteStats.php" script to update the internal statistics cache (see Manual:Maintenance scripts ).

There are several reasons you might 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 namespaces require additional privilege(s) for editing.
• You want certain namespaces not to be subjected to certain limitations or default settings ($wgNoFollowNsExceptions for example)
• A uniform prefix for specific content(s), which is searchable for that namespace only
• If you're a MW developer, sometimes you need to have a custom namespace for your extension(s)

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.

You can use the NamespaceDupes maintenance script to correct this problem. It will find pages in the main namespace with a prefix matching any of the defined namespaces, and update their records.

If you are not able to run maintenance scripts, then the following approach might be suitable:

1. Comment out the namespace definition in the configuration file
2. Access each affected page (use Special:PrefixIndex on your wiki to find them), 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

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.

You can use the CleanupTitles maintenance script to correct this problem. It will find pages any namespace that is no longer defined, and update their records. The pages will be moved to the main namespace with an added prefix like NS123:, unless specified otherwise by parameters to the script.

As above, you can also temporarily restore the namespace configuration and move the pages from the user interface (or delete them).

Suppose that you need to rename custom namespace "Foo" to "New" without performing a mass move of pages. The easiest way to achieve this is to preserve the namespace ID (here "3000") as well as the namespace constant (here "NS_FOO"), modify the (visible) namespace title and add the old one as an alias.

change

define("NS_FOO", 3000);
$wgExtraNamespaces[NS_FOO] = "Foo";

to

define("NS_FOO", 3000);
$wgExtraNamespaces[NS_FOO] = "New";
$wgNamespaceAliases['Foo'] = NS_FOO;

Note that some extensions store namespace names in plain text instead of their internal IDs, and should therefore be dealt with extra care. Examples include:

• The Translate extension creates pages with the source page's name (containing the namespace prefix) under the Translations namespace, e.g. Translations:Manual:Using custom namespaces/117/es for the Spanish translation of the 117th message on this page. When you change the namespace's name, translatable pages should be handled as if they were moved .

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.

The simplest way of setting the background color of pages in a particular namespace (and its associated talk namespace) is by adding the following code to your common.css:

.ns-3000 #content, .ns-3001 #content { background-color: #f3f3ff; }
.ns-3000 div.thumb, .ns-3001 div.thumb { border-color: #f3f3ff; }

where 3000 is the namespace's index and #f3f3ff  is the color you want as its background color. However, unless your needs are very basic you will probably want to support night mode as it is expected by modern standards, and avoid accessibility problems derived from using fixed colors. See Recommendations for night mode compatibility on Wikimedia wikis for details.

You might also want to change the name of the tab from its default (the namespace's name). This is located in your system messages at MediaWiki:nstab-namespace.

• Manual:Namespace
• Namespace manager – as originally proposed for MW1.6-wikidata and its successors. Currently in use by the OmegaWiki project.

• Manual:Configuration settings
  • Manual:Configuration settings#Namespaces
  • $wgNamespacesToBeSearchedDefault
• Maintenance scripts

• Category:Namespace extensions
• Extension:NamespaceManager – for management of namespaces
• Extension:BlueSpiceNamespaceManager – lets you create custom namespaces
• Extension:SpecialNamespaces – a modified version of the Extension:Interwiki which changes it to provide a namespace manager as a special page.
• Extension:Lockdown – to control access to namespaces

• Extension namespace registration – List of custom namespaces registered by extensions. If you define a constant for a custom namespace, list it here, too.

• MediaWiki configuration
• Namespace