I've implemented an extension to the [[MediaWiki:Bad image list]] feature.
You can now specify a list of exceptions, i.e. articles where the image is
allowed to be displayed inline. The typical format is:
* [[:Image:Penis.jpg]] except on [[Penis]]
The text "except on" is ignored, it is not special. Only the links are
relevant.
I've documented the format at:
http://en.wikipedia.org/wiki/MediaWiki:Bad_image_list
-- Tim Starling