[core] AD Review of draft-ietf-core-problem-details-04

[Francesca Palombini <[e-mail]>]

# AD Review of draft-ietf-core-problem-details-04

cc @fpalombini

Thank you for this short and well written document.

No major comments from me, only a couple of minor comments, which you can address together with any other Last Call comments.

At the same time as Last Call, I will also request an I18ndir review for Appendix A, which I think would benefit from expert I18n eyes.

## Comments

### SHOULD

Section 2:
>      A short, human-readable summary of the problem shape.  It SHOULD
>      NOT change from occurrence to occurrence of the same problem
>      shape.

Needs some context around why this is a SHOULD and what are the reasonable cases and consequences of this recommendation not being followed.

### Untagged text strings for human readable text

Section 2:
>   Both "title" and "detail" can use either an unadorned CBOR text
>   string (text) or a language-tagged text string (tag38); see
>   Appendix A for the definition of the latter.

I have a hard time motivating why this can be unadorned CBOR text string, given that these two fields are always human-readable text. Maybe we need to add a default, i.e. that when text used, that is to be interpreted as English language is used.

### More examples

It would be nice with an example in Section 3.1 as well.

### Example's format

Section 3.2:
>   An example of a custom extension using a URI as custom-problem-
>   detail-entries key is shown in Figure 3.

Please explicitly state that the example (or examples if you add one in Section 3.1) uses CBOR diagnostic notation.

### "like this"

Section 3.2:
>        /example value 4711 not actually registered like this:/

I don't get the sentence above - if this is to highlight that this is an example and that the value 4711 is not actually registered, I think this is redundant (and you could also add that in the Figure caption rather than in the example's text).

### Reference for tunnel-7807 registration

Section 5.2:
>      +=======+=============+===========================+===========+
>      | 7807  | tunnel-7807 | Carry RFC 7807 problem    | RFC XXXX  |
>      |       |             | details in a Concise      |           |
>      |       |             | Problem Details data item |           |
>      +-------+-------------+---------------------------+-----------+

Please change the reference to "RFC XXXX, Appendix B".

## Notes

This review is in the ["IETF Comments" Markdown format][ICMF], You can use the
[`ietf-comments` tool][ICT] to automatically convert this review into
individual GitHub issues.

[ICMF]: https://github.com/mnot/ietf-comments/blob/main/format.md
[ICT]: https://github.com/mnot/ietf-comments