Code Snippet Explanation Requested

I have inherited a php application that includes the following code snippet:

<?=$User->get_css( "" );?>

Code (markup):

I do not understand the prepended '='. I have searched the php manual, but cannot find a description of what this does. Am I just missing it in the php manual?

 

It's designed to output the contents of an expression without using print or echo.

I don't remember if asp_tags has to be on in php.ini for it to work or not.

 

'asp_tags' doesn't affect it though 'short_open_tag' does. Seeing as 'short_open_tag' is being deprecated, you will eventually have to replace it with the 'long hand' version:
<?php echo $User->get_css( "" );?>

 

Never would have thought you can't do this,

<?php='stuff';?>

Code (markup):

but apparently you can't.
The = throws an unexpected character error.