OCI image-spec and distribution-spec 1.1 release is imminent.

• The distribution spec requires (“MUST”) clients to add compatibility code to support “subject”/“referrer”s for pre-1.1 registries. (This is potentially relevant for signatures, SBOMs, attestations and the like, I’m not sure how much it is used in practice).
• We should probably add support for storing sigstore signatures with the “subject” feature (assuming cosign does support that)
• The image spec has added requirements about preserving unknown fields and not failing when encountering unknown MIME types. We probably need a code audit, and perhaps unit tests.

See the checklists in https://github.com/containers/image/issues/2030 for more details.

(The comparatively low-hanging fruit is https://github.com/containers/image/pull/2062 .)