Today while working on a project where we had collaborated with freelance developers I noticed that some pages weren’t looking as they should. A quick glance at the code revealed that the developer was using “short tags” to include the header.
<? get_header ?>
To use short tags, the short_open_tag option must be turned on in php.ini. On most servers short_open_tag is turned on, but alot of servers (like my local server) has it turned off.
If you are developing a theme for a specific server environment, this may be acceptable. But if you are developing a theme or a plugin to be used by a lot of people on a lot of different server environments then short tags can not be used!