Many thanks to marcanth, and his source Roger Johansson, for a GREAT script I've already given 5 stars. Problem was I couldn't get the image to work, and then found a character map symbol which worked in Stylish, but not in userContent. I've put the image BEFORE the link, and rewritten the code more precisely thanks to Pawe� Kubisz (cyberrus) and the PDF icon script ("a[href]") - and come up with this PNG/base 64 version which works BOTH in Stylish and userContent. I'm grateful to marcanth for finding this as now, even with my black background Google IMage Search script in effect, I still get an indicator of "visited image" as well as links (see screenshots).