Manual:$wgAvailableRights

Access: $wgAvailableRights
A list of available rights, in addition to the ones defined by the core.
Introduced in version:	1.13.0 (r34357)
Removed in version:	Still in use
Allowed values:	(array of strings)
Default value:	`[]`
Other settings: Alphabetical \| By function

Details

The list of core user rights is defined in PermissionManager.php, $coreRights. See Manual:User rights#Adding new rights.

Extensions (until MediaWiki 1.24) use this variable instead, like:

$wgAvailableRights[] = 'ninja-powers';

MediaWiki version:

≥ 1.25

Since MediaWiki 1.25 do in extension.json :

	"AvailableRights": [
		"ninja-powers"
	],