Short or short-open tags look like this:
<?...?>
Short tags are, as one might expect, the shortest option You must do one of two things to enable PHP to recognize the tags:
Choose the --enable-short-tags configuration option when you're building PHP.
Set the short_open_tag setting in your php.ini file to on. This option must be disabled to parse XML with PHP because the same syntax is used for XML tags
(XML:extensible markup language)