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      

<ismap>

empty
start tagrequired
end tagforbidden
Sandia Reference
Link to Site Map

this is used in server-side image mapping.