Basicaly CLASS:[insert class name(s) here] (or something along those lines), so by adding for
example CLASS:nsd to an image (for example embeded via a "no source" template) a class="nsd"
atribute would be added to the image tag on all pages that use the image.
"highlighted" in certain ways automaticaly.
I realise this might be slightly tricky to achieve. For example if the keyword is added to a
template that is transcluded on a number of images all those images would need to have theyr
class data updated, and that would mean that all articles that use those images would in turn
have to be re-parsed for the change to actualy have any noticable effect. I guess the first part
is easy enough as the job que will already work it's way though all pages that transclude a
changed template, but this would call for all pages that use those images touched by the job que
to also be added to the job que (preferably if and only if the "class data" was changed to avoid
a massive "cascade" due to a simple typo fix). Not sure how problematic this would be.
sure there are lots of usefull applications for an ability to asign a class to an image beyond
highlighting images slated for deletion.