I've been using Cowering's Good tools for a while now to audit my roms. I've also occasionally used the clrmame datfiles to audit my roms. I've noticed 2 things

One is that cowering seems to be really upset about people reverse engineering his tools and pulling the crc lists out of them to incorporate into other programs. Is this what has been done with the Dat files here or have these dat files simply been created straight from clrmame on folders audited with Goodtools to be 100% complete?

The other thing is that I've noticed that in just about every case the dat file will give me a slightly different output from the GoodTools. It seems there are numerous cases where the Clrmame dat file will label a rom file as uneeded despite the fact that the GoodTools will recognize the file fine and even tell you the correct crc32.