diff --git "a/include/class-mw\\Ns.php" "b/include/class-mw\\Ns.php"
index 9b30ff1..2b9500d 100644
--- "a/include/class-mw\\Ns.php"
+++ "b/include/class-mw\\Ns.php"
@@ -1,270 +1,279 @@
 <?php
 # Boz-MW - Another MediaWiki API handler in PHP
-# Copyright (C) 2017, 2019 Valerio Bozzolan
+# Copyright (C) 2017, 2019, 2020, 2021 Valerio Bozzolan
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 # GNU Affero General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 # MediaWiki
 namespace mw;
 
 /**
  * A Namespace.
  *
  * Yes, PHP does not allow to call a class "Namespace".
  */
 class Ns {
 
 	/**
 	 * @var int
 	 */
 	private $id;
 
 	/**
 	 * @var object
 	 */
 	private $name;
 
 	/**
 	 * @var object
 	 */
 	private $canonicalName;
 
 	/**
 	 * Aliases of this namespace
 	 *
 	 * @var array
 	 */
 	private $aliases = [];
 
 	/**
 	 * Constructor
 	 *
 	 * @var $id int
 	 * @var $name string
 	 * @var $aliases array
 	 */
 	public function __construct( $id, $name, $aliases = [] ) {
 		$this->setID( $id );
 		$this->setName( $name );
 		$canonical_name = self::existsDefaultCanonicalName( $id )
 			? self::defaultCanonicalName( $id )
 			: $name;
 		$this->setCanonicalName( $canonical_name );
 		foreach( $aliases as $alias ) {
 			$this->addAlias( $alias );
 		}
 	}
 
 	/**
 	 * Get the namespace ID
 	 *
 	 * @return int
 	 */
 	public function getID() {
 		return $this->id;
 	}
 
 	/**
 	 * Get the local namespace name (eventually localized)
 	 *
 	 * @return string
 	 */
 	public function getName() {
 		return $this->name->get();
 	}
 
 	/**
 	 * Get the namespace canonical name (in English)
 	 *
 	 * @return string
 	 */
 	public function getCanonicalName() {
 		return $this->canonicalName->get();
 	}
 
 	/**
 	 * Set the namespace ID
 	 *
 	 * @param $id int
 	 * @return self
 	 */
 	public function setID( $id ) {
 		$this->id = $id;
 		return $this;
 	}
 
+	/**
+	 * Check if this namespace is a Category:
+	 *
+	 * @return bool
+	 */
+	public function isCategory() {
+		return $this->getID() === 14;
+	}
+
 	/**
 	 * Set the namespace name
 	 *
 	 * @param $name string
 	 * @return self
 	 */
 	public function setName( $name ) {
 		$this->name = new NsPart( $name );
 		return $this;
 	}
 
 	/**
 	 * Set the namespace canonical name
 	 *
 	 * @param $name string
 	 * @param $id int
 	 * @return self
 	 */
 	public function setCanonicalName( $name ) {
 		$this->canonicalName = new NsPart( $name );
 		return $this;
 	}
 
 	/**
 	 * Add another namespace alias
 	 *
 	 * @param $alias string
 	 * @return self
 	 */
 	public function addAlias( $alias ) {
 		$this->aliases[] = new NsPart( $alias );
 		return $this;
 	}
 
 	/**
 	 * Get all namespace parts
 	 *
 	 * @return array
 	 */
 	public function getParts() {
 		$all = [];
 		$all[] = $this->name;
 		if( $this->isCanonicalNameDifferent() ) {
 			$all[] = $this->canonicalName;
 		}
 		foreach( $this->aliases as $alias ) {
 			$all[] = $alias;
 		}
 		return $all;
 	}
 
 	/**
 	 * @deprecated
 	 * @return array
 	 */
 	public function getAllTitlePartsCapitalized() {
 		return $this->getParts();
 	}
 
 	/**
 	 * Get a regex that matches this namespace
 	 *
 	 * @param $args array
 	 * 	wikilink: flag indicating that the NS is inside a wikilink
 	 * @return string
 	 */
 	public function getRegex( $args = [] ) {
 
 		// default arguments
 		$args = array_replace( [
 			'wikilink' => true,
 		] , $args );
 
 		$all = [];
 		foreach( $this->getParts() as $part ) {
 			$all[] = $part->getRegex();
 		}
 
 		// category corner-case: a wikilink to a category has the ':' prefix
 		$catprefix = '';
 		if( $args[ 'wikilink' ] && $this->getID() === 14) {
 			$catprefix = ':';
 		}
 
 		// in case of a single part we can avoid the OR group
 		if( count( $all ) === 1 ) {
 			return $catprefix . $all[ 0 ];
 		}
 
 		// return an 'OR' query, without creating a group
 		$or = implode( '|', $all );
 		return $catprefix . "(?>$or)";
 	}
 
 	/**
 	 * Check if the canonical name is different from the local one
 	 *
 	 * @return bool
 	 */
 	public function isCanonicalNameDifferent() {
 		return $this->getName() !== $this->getCanonicalName();
 	}
 
 	/**
 	 * Check if it exists this default canonical name (from ID)
 	 *
 	 * @param $id int
 	 * @return boolean
 	 */
 	public static function existsDefaultCanonicalName( $id ) {
 		return array_key_exists( $id, self::defaultCanonicalNames() );
 	}
 
 	/**
 	 * Get the default canonical name from its ID
 	 *
 	 * @param $id int
 	 * @return boolean
 	 */
 	public static function defaultCanonicalName( $id ) {
 		if( ! self::existsDefaultCanonicalName( $id ) ) {
 			throw new \Exception('unexisting namespace ID');
 		}
 		return self::defaultCanonicalNames()[ $id ];
 	}
 
 	/**
 	 * Normalize a namespace name
 	 *
 	 * @param $name string
 	 * @return string
 	 */
 	public static function normalizeName( $name ) {
 		return ucfirst( strtolower( trim( $name ) ) );
 	}
 
 	/**
 	 * Get all the known MediaWiki default canonical names
 	 *
 	 * @return array
 	 */
 	public static function defaultCanonicalNames() {
 		return [
 			0  => '',
 			1  => 'Talk',
 			2  => 'User',
 			3  => 'User talk',
 			4  => 'Project',
 			5  => 'Project talk',
 			6  => 'File',
 			7  => 'File talk',
 			8  => 'MediaWiki',
 			9  => 'MediaWiki talk',
 			10 => 'Template',
 			11 => 'Template talk',
 			12 => 'Help',
 			13 => 'Help talk',
 			14 => 'Category',
 			15 => 'Category talk',
 			-1 => 'Special',
 			-2 => 'Media'
 		];
 	}
 }