diff --git "a/include/class-wb\\Statement.php" "b/include/class-wb\\Statement.php"
index f246b72..bb1bdb6 100644
--- "a/include/class-wb\\Statement.php"
+++ "b/include/class-wb\\Statement.php"
@@ -1,162 +1,180 @@
 <?php
 # Boz-MW - Another MediaWiki API handler in PHP
 # Copyright (C) 2017, 2018 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/>.
 
 # Wikibase
 namespace wb;
 
 /**
  * A Statement is a type of Claim with references and a rank.
  *
  * @see https://www.wikidata.org/wiki/Wikidata:Glossary#Statement
  */
 class Statement extends Claim {
 
 	/**
 	 * ID of the statement (if any)
 	 *
 	 * @var string|null
 	 */
 	private $id;
 
 	/**
 	 * Type of the statement
 	 *
 	 * I think that it's hardcoded to 'statement' in Wikibase.
 	 *
 	 * @var string
 	 */
 	private $type = 'statement';
 
 	/**
 	 * Rank of this statement
 	 *
 	 * @var string
 	 */
 	private $rank = 'normal';
 
 	/**
 	 * Get the type
 	 *
 	 * @return string
 	 */
 	public function getType() {
 		return $this->type;
 	}
 
 	/**
 	 * Get the rank
 	 *
 	 * @return string
 	 */
 	public function getRank() {
 		return $this->rank;
 	}
 
 	/**
 	 * Check if this statement has an ID
 	 *
 	 * @return boolean
 	 */
 	public function hasID() {
 		return isset( $this->id );
 	}
 
 	/**
 	 * Get the ID (if any)
 	 *
 	 * @return string|null
 	 */
 	public function getID() {
 		return $this->id;
 	}
 
 	/**
 	 * Get the ID (if any)
 	 *
 	 * @return string|null
 	 */
 	public function setID( $id ) {
 		$this->id = $id;
 	}
 
 	/**
 	 * Set the type
 	 *
 	 * @param string $type
 	 * @return self
 	 */
 	public function setType( $type ) {
 		$this->type = $type;
 		return $this;
 	}
 
 	/**
 	 * Set a rank
 	 *
 	 * @param  string $rank
 	 * @return self
 	 */
 	public function setRank( $rank ) {
 		$this->rank = $rank;
 		return $this;
 	}
 
+	/**
+	 * Set the rank as "preferred"
+	 *
+	 * @return self
+	 */
+	public function setRankPreferred() {
+		return $this->setRank( 'preferred' );
+	}
+
+	/**
+	 * Set the rank as "deprecated"
+	 *
+	 * @return self
+	 */
+	public function setRankDeprecated() {
+		return $this->setRank( 'deprecated' );
+	}
+
 	/**
 	 * Create a statement from raw data returned from API responses
 	 *
 	 * @param $data array
 	 * @return self
 	 */
 	public static function createFromData( $data ) {
 		if( ! isset( $data['type'], $data['rank'] ) ) {
 			throw new WrongDataException( __CLASS__ );
 		}
 		$statement = parent::createFromData( $data );
 		$statement->setType( $data['type'] );
 		$statement->setRank( $data['rank'] );
 		if( $data['id'] ) {
 			$statement->setID( $data['id'] );
 		}
 		if( $data['references'] ) {
 			$statement->setReferences( References::createFromData( $data['references'] ) );
 		}
 		return $statement;
 	}
 
 	/**
 	 * Convert this object to an associative array suitable for JSON encoding
 	 *
 	 * @return array
 	 */
 	public function toData() {
 		$data = parent::toData();
 
 		// statement ID
 		if( $this->hasID() ) {
 			$data['id'] = $this->getID();
 		}
 
 		// statement type
 		$data['type'] = $this->getType();
 
 		// statement rank
 		$data['rank'] = $this->getRank();
 
 		return $data;
 	}
 
 }