Understood Phil. I am getting there. Have played with your last command and output xmp file from Lightroom and Acdsee. What I note is that Acdsee /Viewnx seem to take note of keywords / Categories / Captions from xmp-dc fields whereas Lightroom seems to ignore those fields and take note of the ipct fields instead.
Also Lightroom adds a whold bunch of other xmp-crss fields which I don't need.
Acdsee when writing directly to a jpg file seems to understand the issues by duplicating xmp-dc to iptc fields. This means that most apps will see keywords and categories.
Now I think what I might do (primarily because I can output the fields I require) is use Acdsee to output the xmp file for my Raw file. However, when I import it using your suggested line:
exiftool "-xmp<=%%d/%%f.xmp" -ext nef .
The iptc fields are not written to, so Lightroom won't see the data.
Is there an easy way to duplicate this in the line above or should I run a second batch file to copy fields within? Maybe something like:
exiftool -TagsFromFile @ "-xmp-dc:subject>iptc:keywords" -ext NEF .
exiftool -TagsFromFile @ "-xmp-dc:description>iptc:description" -ext NEF .
I must admit since I started to look into all this I'm finding it a bit of minefield. Each app seems to take different fields also making it hard to transfer fields like ratings / urgency / labels etc. I'm not sure I can deal with ratings as the field itself seems to be non-standard
Ideally I'd like to keep the workflow as simple as possible keywording / ratings or urgency / categories and have them readable by most apps that I use.
To answer your question: I use a Nikon D300, often taking jpg+NEFs although this may vary in favour of JPG or NEF alone. Apps used are Nikon Viewnx / Capture NX2 / Lightroom and Acdsee pro 2.5
The latter is a recent consideration because it has a fairly powerful database, can deal with xmp output, writes directly to jpgs and deals with offline media which is important to me.
Thanks for the useful utility and your help, I really feel I'm getting somewhere now after many many years of frustration.