As far as I'm aware, when listing items for auction as against bin, multiple listings are permitted.:-)

I thought it was any multiple of exactly same item - auction or BIN.  You could list say red T-shirt in size 10, 12, and 14, but not 2 red T-shirts size 12. But you could list red size 12 and blue size 12.

The whole point is that large sellers do not flood eBay with pages and pages of the same item. 

So I do not think you are allowed to list the same book twice, not even with a different photo.  But could somebody put up the actual rule, please?

I really would like to know for sure; have some items that I would like to list separetly, but people may want them as set.  Like chairs and lamp shades.  Listing them as set may put off buyers who only need one.