Well, THAT experiment was an excellent example of why you should not trust cloud services.
I understood from the start that Google had migrated from Picasa to Google Photos in 2016. But Google Photos didn’t recognize the XMP Face metadata created by Picasa! The only metadata it found compatible was the Caption.
It was expected that the IDs wouldn’t survive.
It did not not even recognize the Face rectangles existed.
I wonder if that is due to the linkrot in the DTD URIs? A number of the domains referenced for the Data Type schemas no longer exist. Does this cause the XML readers to crap out?
If so, is this a vulnerability in the Gramps XML format too?
In 50 years, will our XML files be uninterpretable because the domain for the RELAX NG schema is has suffered linkrot or was clobbered?