Are PHP short tags acceptable to use?

Here's the information [according to the official documentation][1]: > There are four different pairs of > opening and closing tags which can be > used in PHP. Two of those, `<?php ?>` > and `<script language="php"> </script>`, > are always available. The other two > are short tags and ASP style tags, and > can be turned on and off from the > php.ini configuration file. As such, > while some people find short tags and > ASP style tags convenient, they are > less portable, and **generally not > recommended**. In my experience most servers *do* have short tags enabled. Typing <?= is far more convenient than typing <?php echo The programmers convenience is an important factor, so **why** are they not recommended? [1]: http://www.php.net/manual/en/language.basic-syntax.php