docker://. But that doesn't seem to be the actual issue anyway, they quoted docs which say it's equivalent.ostree-unverified-image:registry: and ostree-unverified-image:docker://, but discover only currently expects ostree-unverified-registry:, not anything else, so ostree-unverified-image:registry: or ostree-unverified-image:docker:// which should both be equivalent cause it to not work properly.docker://ostree-unverified-image:registry:ostree-unverified-image:registry:ostree-unverified-image:docker://ostree-unverified-image:docker://ostree-unverified-registry: