Possibly.....maybe?
Full Tilt
Here is the xml file (named 'username.xml' in the FT directory) contents showing a couple of generic note entries....
<?xml version="1.0" encoding="UTF-8"?>
<!-- Do not edit this file -->
<PLAYERDATA version="1.0" xsi:schemaLocation="http://www.fulltiltpoker.com/schemas/client http://www.fulltiltpoker.com/schemas/client/PlayerNotes.xsd" xmlns="http://www.fulltiltpoker.com/schemas/client" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<NOTES>
<NOTE PlayerId="Player 1" ColourIx="4" Text="Player 1 Note" />
<NOTE PlayerId="Player 2" ColourIx="7" Text="Player 2 Note" />
</NOTES>
</PLAYERDATA>
each <NOTE> entry holds the player's name, the color you assigned (as a number) and the text you entered in the site.
The
<!-- Do not edit this file --> seems clear, and it is likely that this file gets overridden from the server somehow, maybe even on each login?
I am basing that on this
xsi:schemaLocation="http://www.fulltiltpoker.com/schemas/client http://www.fulltiltpoker.com/schemas/client/PlayerNotes.xsd" xmlns="http://www.fulltiltpoker.com/schemas/client" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" sounding like a server script.
Obviously, entering them in through the software while you review the HHs is possible, but not very useful and you have to search for the names to do that.
I don't see the similar file at Pokerstars....