Page header when printing message

[BW]

When I open an email message and click on File|Page Setup|Memo Style , it
opens a window that has "Header/Footer" in the middle of the window. In the
"Header" line I see the following:

&w&bPage &p of &P

What does the "&w" and the "&b" mean? I can figure out the rest of the line
but was wondering what those two 'commands' do. What other
options/codes/letters are available and what do they do? I searched through
the Help file in Outlook but couldn't find any reference to this. Is there
someplace where these are documented?

Thanks,
BW