public function code( $typedescription, $includeSpecials = false ) {
		$r = ((isset($this->sqltype_typeno[$typedescription])) ? $this->sqltype_typeno[$typedescription] : self::C_DATATYPE_SPECIFIED);
		if ($includeSpecials) return $r;
		if ($r > self::C_DATATYPE_SPECIFIED) return self::C_DATATYPE_SPECIFIED;
		return $r;
	}