[Cellar] Re: Gorry Fairhurst's Discuss on draft-ietf-cellar-tags-20: (with DISCUSS and COMMENT)

[Steve Lhomme <[e-mail]>]

Hi Gorry,

Thanks for a review. My comments below:

> On 18 Dec 2025, at 17:17, Gorry Fairhurst via Datatracker <[e-mail]> wrote:
> 
> Gorry Fairhurst has entered the following ballot position for
> draft-ietf-cellar-tags-20: Discuss
> 
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> for more information about how to handle DISCUSS and COMMENT positions.
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> 
> The document, along with other ballot positions, can be found here:
> https://datatracker.ietf.org/doc/draft-ietf-cellar-tags/
> 
> 
> 
> ----------------------------------------------------------------------
> DISCUSS:
> ----------------------------------------------------------------------
> 
> I have two document concerns: Relating to current text that says: "Matroska Tag
> Names for binary data are to be allocated according to the "Specification
> Required" policy [RFC8126]."
> 
> * I support the DISCUSS by Med, relating to the need for additional text in the
> IANA Section on the Specification required policy, and guidance for Designated
> Experts (DE).

OK, now I understand what DE stands for.

This should be handled the same way as we have some Matroska IDs that have a "Specification Required” policy: https://www.rfc-editor.org/rfc/rfc9559#name-matroska-element-ids-regist
One-octet and two-octet Matroska Element IDs.

The experts have been assigned for these (Dave and myself): https://www.iana.org/assignments/matroska/matroska.xhtml#matroska-element-ids 

> * I'd like to DISCUSS the use the word "Official" in this I-D, because I find
> this is an unusual word to use in an IETF Specification to describe an entry in
> an IANA Registry. I'd expect to see a word such as "assigned" or "allocated".

This is the terminology we have used in the documentation for 20+ years and that was carried over to this document.
I replaced Official with Assigned as you suggested and it does work better IMO: https://github.com/ietf-wg-cellar/matroska-specification/pull/1048

We may not even need to specify that “assigned” elements are the one in the IANA registry in https://github.com/ietf-wg-cellar/matroska-specification/pull/1047 since that’s the terminology used in the IANA regsitry.

> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
> 
> I have several comments that I hope may improve this:
> 
> 1. Please could you make this abstract more descriptive? It's hard to
> understand what the document might contain from the abstract. There are many
> sentences in the introduction that would help. For example these text fragments
> could be helpful;:
> 
> Matroska is a multimedia container format that can store timestamped multimedia
> data but also chapters and tags. ... This document defines  ... a set of common
> tag names used in Matroska. These Tag elements add metadata to identify and
> classify the information found in a Matroska Segment. ...

I reordered the text so that it starts with something more general in https://github.com/ietf-wg-cellar/matroska-specification/pull/1050 

> 2. The document contains the names of several example physical entities in the
> entertainment industry. I am not yet persuaded that this necessary or even
> helpful to have actual rather than exemplar identities named.

This issue is addressed by https://github.com/ietf-wg-cellar/matroska-specification/pull/1045 

> 3. There is a section on Official Tags, which says: "The following is a
> complete list of the supported Matroska Tags." -- Is that the present value?
> The only permitted value until this RFC-to-be is updated? This is often phrased
> as /complete/assigned/ or some similar change (see DISCUSS point).

This is indeed not the complete and final list of tags but the initial list. This is addressed in https://github.com/ietf-wg-cellar/matroska-specification/pull/1049 

Thanks again for your review.