How can I find files on Wikipedia (or the Wikimedia Commons) that are in two or more specific categories? For instance, if I was searching for files to put into the category "dogs and cats", I would want to find all of the files that were in both the category "dogs" and the category "cats." How can this be accomplished?
migrated from superuser.com Jul 4 '12 at 22:20
You can use CatScan to do that.
For example, to query files on Commons, you can start with http://toolserver.org/~magnus/catscan_rewrite.php?language=commons&project=wikimedia&ns=1 and enter the categories you want into the Categories box.