<comment>
container
w3c icon + 2.0 3.0 3.2 4.0
Netscape icon 1.0 2.0 3.0 4.0  
MSIE icon 1.0 2.0 3.0 4.0  
Mosaic icon 1.0 2.0      
Opera 1.0 2.1      
WebTV 0.9 1.2      

<!-- ... -->
empty
w3c icon + 2.0 3.0 3.2 4.0
Netscape icon 1.0 2.0 3.0 4.0  
MSIE icon 1.0 2.0 3.0 4.0  
Mosaic icon 1.0 2.0      
Opera 1.0 2.1      
WebTV 0.9 1.2      

<comment> or
<!-- ... -->


Link to Site Map

<comment> ... </comment>

<comment>this is the comment structure stipulated by Microsoft.</comment>. However, the laws of HTML dictate that a browser ignore any tag it doesn't recognize and the content within so you really don't have to worry about either use.

<!-- your comment here -->

<!-- This is the more universal comment structure, recommended in HTML 2.0. -->

WebTV describes a difference...

"However, because the <comment> tag can only be used to comment out text, not tags, WebTV Networks recommends using the HTML 2.0 "<!-- ... -->" comment tag."