Here's a short field guide on the three metadata signals that out a lot of AI images: C2PA content credentials (Adobe/OpenAI/Google/MS, since early 2024), the XMP DigitalSourceType flag, and the old EXIF Software field. Including a 2026 comparison of what each major generator tags. The method breaks the moment someone screenshots or re-saves the image, so it's a confirm-not-deny tool. Spelled out in the post. Disclosure: I make the iOS app it references; the technique is tool-agnostic. ht...