[dispatch] draft-ietf-dispatch-mime-protobuf-03 ietf last call Artart review

[Darrel Miller via Datatracker <[e-mail]>]

Document: draft-ietf-dispatch-mime-protobuf
Title: Media Type Registration for Protocol Buffers
Reviewer: Darrel Miller
Review result: Ready with Issues

This is an ART area review of
https://www.ietf.org/archive/id/draft-ietf-dispatch-mime-protobuf-03.html

## Issues:

### Section 4. Encoding Considerations

> For binary forms that need to transit non-binary transports, a base64
Content-Transfer-Encoding (xref to [RFC4648]) is recommended.

I worry that this statement might lead people to think they should use this as
a header in HTTP, when RFC7231 says it should not be
https://www.rfc-editor.org/rfc/rfc7231#appendix-A.5.

Perhaps simply saying the following would be safer:

> For binary forms that need to transit non-binary transports, a base64
encoding (xref to [RFC4648]) is recommended.

### 7.1. Registration

> Protobuf implementations should accept all versions of wire encodings defined
at the time of implementation.

Is it appropriate to state this requirement in a media type registration?
Should this not be content of the protobuf specification instead?

## Nits:

### 6. Security Considerations

> While it is common for a protobuf definition to be used as input to a code
generator which then produces something executable, but that applies to the
schema language, not serializations.

There is something grammatically off with the "While ..., but" part of this
sentence. I think the "but" can be removed.

In general this doc looks good to me.

Darrel