Hi Mario,
Not a big issue but just wondering why I always have to writeback the metadata for PDF-files 2 times. After the first write the pencil re-appears; after the second write not. I don't see this with (e.g.) JPG's.
Could you please tell me how to find out what's going on?
Thanks in advance,
Rien.
Have a look at Metadata Problems and Pitfalls (https://www.photools.com/help/imatch/md_for_beginners.htm?dl=md_problems) which covers this case and gives possible explanations. My bet would be PDF keywords not matching your keyword settings, flattening rules and thesaurus. This will also depend on which software was used to produce or edit the PDF. Something along that, most likely.
Run the Metadata Analyst (https://www.photools.com/help/imatch/app-md-analyst.htm?dl=hid-1) on a "fresh" PDF for some additional insights.