function deleteTag( $tag, $blog_id, $tag_group, $for_real = false ) {

		/** @var $wpdb \wpdb */
		global $wpdb;

		// Get ID

		$sql = "SELECT id FROM {$this->dbTagsTable} WHERE tag = %s ";
		$tag_id = $wpdb->get_var( $wpdb->prepare( $sql, $tag ) ); // @codingStandardsIgnoreLine

		if ( ! $tag_id ) {
			return false;
		}

		if ( $for_real && is_super_admin() ) {
			$wpdb->delete(
				$this->dbLinkTable, [
					'tags_id' => $tag_id,
				], [ '%d' ]
			);
			$wpdb->delete(
				$this->dbTagsTable, [
					'id' => $tag_id,
				], [ '%d' ]
			);
			$result = 1;
		} else {
			$result = $wpdb->delete(
				$this->dbLinkTable,
				[
					'users_id' => $this->userId,
					'blogs_id' => $blog_id,
					'tags_id' => $tag_id,
					'tags_group' => $tag_group,
				],
				[ '%d', '%d', '%d', '%d' ]
			);
		}

		// TODO:
		// Optimize the links table: $wpdb->query( "OPTIMIZE TABLE {$this->dbLinkTable} " );
		// Optimize the tags table: $wpdb->query( "OPTIMIZE TABLE {$this->dbTagsTable} " );

		return $result;
	}