A couple years ago I was trying to extract and interpret information from a NAND flash chip. I was able to get a dump of the bytes, and identified the pages and their spare areas. But I never was able to figure out the logical ordering of the pages. What all the bits in the spare areas meant, which pages were bad, etc. So I never was able to reconstruct a logical view of the disk.

I tried reading datasheets, but they didn't seem to have the full picture. Had I know about this document then I might have had a chance at figuring it out.