Just upgraded to MC32, while researching the new MC32 photo tag functionality I found this on Synology's website.
https://kb.synology.com/en-us/DSM/tutorial/What_metadata_standards_does_Synology_Photos_supportNotes:
General tag equals the Subject tag in the XMP standard and the Keywords tag in the IPTC standard. If both values exist, the value of Subject will take effect and be applied to both standards.
Description equals the ImageDescription tag in the Exif standard.
Rating equals the Image.Rating and Image.RatingPercent tags in the Exif standard and the Rating, RatingPercent, and MicrosoftPhoto tags in the Xmp standard.
Photo rotation edits will be written back to the Orientation tag in the Exif standard.
Date taken edits will be written back to the DateTime and DateTimeOriginal tags in the Exif standard.
Posting as an fyi incase anybody else besides me uses MC for tagging and Synology Photos for viewing.
