Hey guys! I wonder, if anybody reads this forum? But I'm developing library that works with NRG images, and without reliable specification I've chances to write code, that would likely create images incompatible with your original software. Is this would be good for you and users?
Anyway I have figured, that header is at the of NRG file, and what each of it's tags mean. Hope, it wont break anything if I define few more tags (like zlib compression) for my use.