This question may be a little unusual for this group but it's fun fun fun!
I have to catalog a one-of-a-kind "artist's book" that contains no text and only a couple of images.
It's basically in codex format, bound, but the pages are absolutely and entirely blank. On the front cover is a little recessed area in which one can see a tiny photograph of a woman. Under that is a protruding "shelf", and hanging on a chain attached next to the recessed area is a similar but much smaller book. The smaller book does have some random French text on its "endpapers," which are just recycled pages, and the artist has signed the back "endpaper." On the back of the big book is a little metal frame enclosing another photo, of four women. The inside back cover of the big book has a cut-out hole in which there's a rock with a little floral drawing on it. A little paper border around the hole has some more random French text, but I don't think the text "chosen" is meant to signify anything.
So the "book" does have two places where there are some random words, and two photographs, and the rock does have a little drawing on its visible surface. But that is the entirety of what I guess we might call the representational content, and it is quite minimal.
Does this need to be cataloged in books format or realia format?
Not long ago I cataloged another one-of-a-kind item by the same artist, but while it also included a tiny attached book and a randomly chosen page of French, it was primarily a primitive wooden sculpture of a bird pierced with lots of screws and nails and attached to a sort of paddle or bread board that was supposed to represent an old-fashioned horn book (the page of French was decoupaged onto it). It seemed pretty clearly a three-dimensional art original and I cataloged it on a realia format. On the other hand, I have cataloged some one-of-a-kind items that were much more "bookish" on books format. They didn't seem like manuscripts, I figured, and were too booklike to just be art originals.
I'm curious what other people will think. Thanks!