First: Yes I used search.

The blocks 43:8-43:14 all say "Stone Slab" regardless of type. These aren't legitimately obtainable, but it's still a bug. (It would also help to note all the Block 43 data values as "Double XYZ Slab" or "XYZ Double-Slab," but I don't want this to be a feature request...)

Also, 44:8-44:14 are bugged as well, and will always place upside-down and can't be combined into Block 43, not to mention the fact that they, similarly to 43, always say "Stone Slab."