Line Feed
A line feed is a whitespace character, that historically represents moving the cursor to the next line, without going back to the beginning of the line.
A line feed is represented by the escape sequence \f, in double quote strings. It is also the ASCII code 12.
Line feed are important when formatting code, as they are at the end of a line.
<?php
echo "\f";
echo chr(12); // ASCII code 12
?>