Sometimes PHP novices attempt to make cleaner or more legible code by copying predefined variables to variables with shortened names prior to working with them. This actually results in doubled memory consumption (when the variable is altered) and therefore slower scripts. In the following example, if a user had inserted 512KB worth of characters into a textarea field this would result in nearly 1MB of memory being used.
$title = strip_tags($_POST['title']); echo $title;
This operation can be performed inline, – avoiding the memory overhead.