Add new comment

To my knowledge it is standard XMP with darktable extensions, see:
https://www.darktable.org/usermanual/en/importing_foreign_xmp.html
I just did some tests with an XMP generated in FRV -> darktable -> (remove additional image file extension from sidecar file) -> FRV -> (add iamge file extension to sidecar file) -> darktable.
Everytime I increased the rating and the change were reflected in the next step.
Thanks
D.Hobbes