The issue: PHP allows several open tags beside "<?php".
echo "Hello world";
Or, even worse.
<?="Hello world"; ?>
<% echo "Hello world"; %>
- <? on its own is reserved for XML declaration
- <?= is complete invalid XML
- <% is ASP style and sucks
- All styles beside the official <?php ... ?> are deprecated
The solution: Stick to standard tags and convert all your scripts!
- Guaranteed to be supported further
- Represents a valid XML processing instruction
- Unique in all PHP documents