For those of us who have been using PHP since the early version 3 days and such, here is a modern day refresher for PHP tags:
If a file is pure PHP code, it is preferable to omit the PHP closing tag at the end of the file. This prevents accidental whitespace or new lines being added after the PHP closing tag, which may cause unwanted effects because PHP will start output buffering when there is no intention from the programmer to send any output at that point in the script.
And from the comment on the same page:
Since PHP 5.4 the inline echo <?= ?> short tags are always enabled regardless of the short_open_tag (php.ini) setting.
For me personally, closing PHP tags are a part of muscle memory. I’ll have to unlearn that, I guess. And in regards to the inline echo tags, I was under the impression that they are being phased out together with the other short tags (<? … ?>). Apparently, I was wrong. They are here to stay. Which explains why there are in PSR-1, PSR-2, and in CakePHP 3 (which requires PHP 5.4.16 and fully adopts PSR-2) in particular.