Kirk
What I'm looking for is an ability - an option - for Photo Mechanic not to display the contents of the XMP <lr:hierarchicalSubject> space.
As I've described and shown in screenshots, seeing the contents of two keyword spaces confuses me. And not just me, other people seem to have the same issue and are attempting to create a complex way out using grep. Carl Seibert mentions this "glitch" in a piece here
https://www.carlseibert.com/keywording-in-photo-mechanic-part-2/ (scroll down to "A Lightroom glitch"). He describes it as "harmless", I disagree. It's certainly preventing me from transitioning to PM+ as my main DAM.
Frankly, I don't think Photo Mechanic has any business reading Adobe's private <lr:hierarchicalSubject> let alone displaying the contents.
I'll try to explain...
"alpha" and the keyword path "[A] | alpha" are two different keywords. There is no duplication here.
Okay, I accept the above example is two different keywords. In Photo Mechanic. But that's only because PM is reading two different XMP spaces and combining them.
But actually they are not two different keywords. "alpha" is a keyword and "[A] | alpha" is not. It is a hierarchical list written by Lightroom to a 'private' XMP space for use by Adobe applications.
How would you edit them otherwise or even see them if we didn't show them together?
I shouldn't be editing my Lightroom Hierarchical Keywords using Photo Mechanic. LR and PM have two different - incompatible - methods of creating and editing this type of controlled vocabulary. If I edit the individual contents of <lr:hierarchicalSubject> in PM by removing the pipe "|" for example it turns a Lightroom hierarchical list into a flat keyword and disrupts the keywords list in Lightroom.
But in any case, there's absolutely no reason to, the keywords exist in the <dc:subject> and that's where they can be edited via PM. So why do we even need to see the contents of <lr:hierarchicalSubject>? Every _keyword_ which exists in <lr:hierarchicalSubject> also exists in <dc:subject>. PM only needs to read and display <dc:subject>.
To reiterate, when I add a keyword which is part of a hierarchy using Lightroom it is written to the usual keywords space <dc:subject> for other applications to read. Additionally that word is written to a private Adobe space as a hierarchy to enable other Adobe applications to recreate that hierarchy.
If the '[A]' is purely for organizational purposes in Lr, one wonders why they output it in the metadata?
So the hierarchical keywords list travels with the image and can move between catalogues and so other Adobe applications such as Bridge can read, write and edit them. The same is true of the develop settings which are also written to the XMP. Adobe Camera Raw can use these settings but not other raw file converters such as Capture One.
Why doesn't Lr just output 'alpha' to the hierarchical keywords?
Because it uses the XMP keyword space <dc:subject> to do that.
Sounds like the only solution that would be satisfactory for you would be to have a separate field for hierarchical keywords. But even then, it's garbage in/garbage out. It would still show it as "[A] | alpha" since that's the value in the metadata.
No, I'm suggesting an option not to view the contents of <lr:hierarchicalSubject>. Lightroom only has a single keywords field but (as shown in the screengrabs I posted above) the option to display either only the keywords or the keywords and the hierarchy (or containing keywords as they describe them there). And, if you look again at the screenshot, Lightroom doesn't show the _exact_ value of the metadata, it strips out the pipes and doesn't duplicate the [A] etc.
Photo Mechanic can't use Lightroom's hierarchical scheme, Structured Keywords are different, Photo Mechanic doesn't need to view this XMP space, there's nothing there for PM which isn't already in the usual keywords <dc:subject>.
I'll leave it for you!
Thanks.