Thanks for another contribution - looks good to me! Will add this to the list for inclusion with our next release.
The _CM at the end of the DAT filename stands for "clrmamepro" (
https://mamedev.emulab.it/clrmamepro/). There was a time when we also used to release DATS formatted for another programme as well, RomCenter, and those had _RC at the end. Those days are gone, but the convention remains for some reason.