I think I get it. It is fo NAND-1 version !!
YAFFS NAND2 does not support over-write of a chunk (until the block is completely erased), however when deleting a chunk, the code overwrites the tags area setting is_deleted field to 1 and then writes the tags to the nand chunk. I can not understand the correctness of this. Please clarify.--
Regards,
Ravi Tandon'Live Free or Die'