\" Print the next character as a double quote rather than treating it as a string terminator
\' Print the next character as a single quote rather than treating it as a string terminator
\n Print a new line character
\t Print a tab character
\r Print a carriage return (used primarily on Windows)
\$ Print the next character as a dollar rather than treating it as part of a variable name
\\ Print the next character as a backslash rather than treating it as an escape character
Here is a code example of these escape sequences in action:
<?php
$MyString = "This is an \"escaped\" string";
$MySingleString = 'This \'will\' work';
$MyNonVariable = "I have \$zilch in my pocket";
$MyNewline = "This ends with a line return\n";
$MyFile = "c:\\windows\\system32\\myfile.txt";
?>