A few days ago I found an .imd-file in Iron Master: The Legendary Blacksmith. When I opened it I found out that it's a file generated by the NNS-exporter for 3ds Max (Nintendo Nitro System). In other words, it's a file containing model data for DS model files. I don't know if other files like this one has been found earlier, but I thought I would tell you about it if that's not the case. As I understand it, the reverse engineered NSBMD-specification isn't complete yet, but this might help it get a step further. If anyone is interested, check out the minigame-folder in Iron Master and you'll find a file called mg05_i00x_r.imd. The generated NSBMD-files are in the same folder as well.