Add an "Unknown" category for Artists
I notice that there is a remarkable lack of art from before the Renaissance, largely due to the apparent requirement that a work of art must be attached to a particular artist. Since it was rare for artists to be credited for their work until the Renaissance (ancient Rome and Greece notwithstanding,) this leaves out a large swathe of historically significant works from WikiArt. This is despite the goal of the website "to cover the entire art history of the Earth – from cave artworks to modern private collections."
To resolve this and broaden the selection of art on the website, it'd be great if there was an "Unknown" category for artists.