 Most conflicts can be ruled out if this extension is only allowed for FAT12 with less than 0xFEF and FAT16 volumes with less than 0x3FEF clusters and 2 FATs.Because these first two FAT entries store special values, there are no data clusters 0 or 1.The first data cluster (after the root directory if FAT12/FAT16) is cluster 2, marking the beginning of the data area.