public static function _init() 
	{	
		// default string
		static::filter( 'any', '[a-zA-Z0-9'.ClanCats::$config->get( 'router.allowed_special_chars' ).']' );
		
		// only numbers
		static::filter( 'num', '[0-9]' );
		
		// only alpha characters
		static::filter( 'alpha', '[a-zA-Z]' );
		
		// only alphanumeric characters
		static::filter( 'alphanum', '[a-zA-Z0-9]' );

		// 404 not found error
		CCRouter::on( '#404', function() 
		{
			return CCResponse::create( CCView::create( 'Core::CCF/404' )->render(), 404 );
		});
	}