I forgot to say that this is one of many Maarten
magics and I think it is running on nlwiki as well.
If you mean by magics that it's not very well documented: Yes that's
true :-(
I just checked the config. I'm keeping 19 unused images pages up to
date right now. For now you can find it at
https://svn.toolserver.org/svnroot/p_erfgoed/erfgoedbot/monuments_config.py
. Look for "unusedImagesPage". I'll put an action point on my list
to make a human readable version of this so it's easier to find.