This is basically a notification of work that I'm going to do soon.
I noticed that one of my images (Moment_arm.png) was still in the upload directory but had disappeared from the DB. I wondered if this was a common problem. I checked using de:, because it's a bit more manageable. I found that out of ~5200 images, more than 60 had no DB entry, not including about 15 images that somehow were uploaded with an initial lower case letter. There were maybe half a dozen valid DB entries with no attached image. I'm going to write a script which reconstructs the missing DB entries, and I'll run it on each language. I imagine the reconstructed entries will be attributed to a user called "(unknown)", or some localised equivalent.
-- Tim Starling.