Just wanted to save this here, from the Content Authenticity Initiative’s FAQ:
Why is there a gap in an image’s CAI data?
If a creator uses a non-CAI-supported tool to edit a piece of content, or if they’re working in a CAI-supported tool without CAI capabilities turned on, then the data of any actions in those spaces won’t be captured. We will make sure to show when this data is missing. The CAI will keep promoting transparency and encouraging the use of CAI-supported editing workflows, but we ultimately believe that any CAI process should be explicitly opted into.
What if CAI data is stripped from an image?
Because CAI does not enforce digital rights management considerations around metadata, it’s possible for individuals or applications to strip CAI data from a file. If you inspect a file on the CAI Verify website and find that it has no Content Credentials, you may be able to find Content Credentials associated with the file on the Verify site by searching for possible matches.