>>I would like to know what the NOSEND does in a <img> tag.
> Nothing.  It doesn't exist.
More precisely, NOSEND does exist, and is not uncommon, but neither is it 
standard HTML, so I'd avoid it.

Theory: When this is present in an IMG tag and set to a value of 1, the 
inclusion of the image is disabled in the situation where someone attempts 
to email the HTML page (or maybe just the image).  So the image is not 
included in the email, just a hyperlink to it.  This is my guess (not 
fact).

Not much info immediately available, but found this:

"The NOSEND attribute will keep Outlook from embedding
the file in the email message.  This will ensure that the link is
forwarded" (found after yahoo search for 'html nosend img')

NOSEND is also used by the WebTV tag DISPLAY "this tag won't let others 
send your e-mail or page" for similar purposes.