Bukkit/CraftBukkit — comment on commit e9e15f3ea53ace543b90883a86fa68601574f6f9
File:  line 0
By mikeprimm:

If you look at the 1.1 code, you'll see that there were other variables, and the nms code actually used them. See \https://github.com/Bukkit/CraftBukkit/blob/1.1-R7/src/main/java/net/minecraft/server/World.java (height, heightBits, heightMinusOne, heightMinusOne) - the method for total height is still around, but the 1.2 code makes little to no use of them (see https://github.com/Bukkit/CraftBukkit/blob/master/src/main/java/net/minecraft/server/World.java - look for the 256's all over the place). The centralization of the height depenedencies that existed in 1.1 is basically gone in 1.2.