When I generate a tileset using ctb-tile, for example:
./ctb-tile zug1.tif -o ../cesium/terrain/zug/
...and then I ask ctb-info about one of the tiles, it tells me something like this:
Child tiles: NW
Tile type: all land
I am surprised by the (correct) list of child tiles. I found no mention of this in the quantized-mesh documentation  and there seems to be no side information (for example, it does _not_ look up the child files in the filesystem).
How is it possible that ctb-info can list the child tiles? Is it just an estimate? Are there some undocumented bits in the quantized-mesh format?