As things stand, only one version of each piece of metadata is accessible for a given image. For audit trails and the like, we may need some mechanism for versioning, including
retrieving older versions (note these will persist in the registry as blobs anyway, so we just need to be able to maintain the references)
retrieving an audit trail of who signed different versions (this may be awkward to retrieve from Notary?)
As things stand, only one version of each piece of metadata is accessible for a given image. For audit trails and the like, we may need some mechanism for versioning, including