Return Carriage

A return carriage is a whitespace character, that historically represents moving the cursor to the beginning of the line, without advancing to the next line.

A return carriage is represented by the escape sequence \r, in double quote strings. It is also the ASCII code 13.

Return carriage are important when formatting code, as they are at the end of a line.

<?php

    echo "\r";
    echo chr(13); // ASCII code 13

?>

Documentation

Related : Line Feed, New Line