Currently, the representation of metadata done with SimpleMetadata class for a serializer that includes nested serializers does not include metadata for the inner fields of the nested serializers. To support the inclusion of nested serializer's inner fields metadata in the representation, I wrote pull request #2911, which works like this:

• introduces the 'serializer' type for fields that are nested serializers
• introduces a 'fields' attribute for fields that are nested serializers, which contains a key/value structure:
  • keys are the field names of the nested serializer
  • values are the metadata representation of the nested serializer's fields

The above will work for nested serializers of arbitrary depth.

However, @tomchristie suggested that a discussion is first opened before going that way, as there may be other ways to represent this. So, let's start this discussion.