$text = preg_replace('#\[mtg=([\r\n]*)([^\s\'\";\+].*?)([\r\n]*)\]([\r\n]*)([^\s\'\";\+].*?)([\r\n]*)\[/mtg]#si', '<a href=\'http://ww2.wizards.com/gatherer/CardDetails.aspx?name=\2\5\' target=\'_blank\'>\2</a>', $text);