Confused about "\n"

As a relatively new PHP programmer, I'm having some confusion about the use
of "\n" to insert a carriage return.

What I'd like to know is: Where exactly can I and can I not insert a "\n"?

Some examples:

echo "<table border='0'>\n"
echo "<table\nborder='0'>"
echo "<p>Information about\n this web site.</p>"

If all of the above are correct, then the answer is "anywhere inside the
quotes surrounding an echo".

But what if you're assigning a variable to be used inside a later echo
statement? Example:

<?php
$thispage = new Page();
$thispage -> Content = "<p>Thank-you for updating the database</p>\n";
$thispage -> DisplayPage ();
?>

And if that's okay, then what about inside single quotes inside the double
quotes of an assignment which will later be used in an echo statement? I
could make my examples ever more complex. But hey, if "\n" is always okay
inside an echo statement, I'll quit worrying about it.

--
Matt Beckwith, M.D.
http://drbeckwith.com

Note that \n causes a line break in your output code, but to cause a line
break in the display of your HTML page you have to use <br>.

--
Markus