The showpiece.php script is not the old way. It is newer than even shortcodes. Both are described on this page in a details section that you have to click on to open. Unlike this script, which draws a piece on a colored space surrounded by a colored border, showpiece.php will draw nothing but the piece, and it will be against a transparent background. While displaying individual pieces with showpiece.php is preferable to using drawdiagram.php, it is mainly intended for use with Game Courier or Interactive Diagrams, and shortcodes remain the best thing to use for illustrating member-submitted rules pages.
The showpiece.php script is not the old way. It is newer than even shortcodes. Both are described on this page in a details section that you have to click on to open. Unlike this script, which draws a piece on a colored space surrounded by a colored border, showpiece.php will draw nothing but the piece, and it will be against a transparent background. While displaying individual pieces with showpiece.php is preferable to using drawdiagram.php, it is mainly intended for use with Game Courier or Interactive Diagrams, and shortcodes remain the best thing to use for illustrating member-submitted rules pages.