CBOR

Summary

The CBOR Working Group held an interim meeting to discuss the status of active working group documents. Due to some initial audio issues and scheduling delays, the meeting began with an open discussion before moving into the primary topics. The technical discussion focused on the ongoing Working Group Last Call (WGLC) for draft-ietf-cbor-serialization and the procedural and technical steps for refining the Concise Diagnostic Notation (EDN) draft, draft-ietf-cbor-edn-literals.

Key Discussion Points

CBOR Serialization and Determinism (draft-ietf-cbor-serialization)

WGLC Status: Laurence Lundblade noted that the WGLC for draft-ietf-cbor-serialization is scheduled to end in a week or two. He noted that he may not be able to attend the next interim meeting due to travel.
Data Model Determinism: Вадим Гончаров asked if the draft includes sections addressing Application Layer Determinism (previously discussed as "ALDR"). Laurence Lundblade clarified that while it does not use the term "ALDR", the draft contains an appendix (Appendix B or C) that discusses determinism at the data model level. The text is intended to remain minimal and non-normative, serving as advice for protocol designers rather than inventing new terminology.
Complex Serialization Offsets: Вадим Гончаров raised specific use cases (e.g., C509 and Bundle Protocol) where an application needs to determine the start and end offsets of a CBOR object within a larger stream. Laurence Lundblade noted that the latest draft contains non-normative text intended to indirectly accommodate these scenarios. Вадим Гончаров suggested that generic CBOR libraries could expose API options utilizing CBOR pointers to return offsets to the application, pointing to the expired draft-ietf-cbor-pointer as a reference.
Feedback Assessment: Paul Hoffman and Laurence Lundblade agreed that WGLC feedback on the mailing list has been constructive and focused primarily on non-normative appendices rather than core serialization mechanics.

Concise Diagnostic Notation (draft-ietf-cbor-edn-literals)

Call for Feature Removals: Christian Amsüss recently initiated a call on the mailing list to identify and discuss controversial features in EDN for potential removal.
Mailing List Procedure:
- Вадим Гончаров asked if proposals to remove features must be sent in separate email threads. Paul Hoffman confirmed that each proposed feature removal should have its own dedicated thread to make tracking, discussion, and consensus-gathering manageable for the chairs and the working group.
- Joe Hildebrand stated he plans to propose the removal of the "ellipsis" feature. To keep discussions focused, he will split this into two separate threads: one proposing the removal of the ellipsis tag, and another proposing the removal of the ellipsis feature itself.
- To minimize repetitive back-and-forth, Joe Hildebrand plans to proactively include known counter-arguments for keeping features within his initial removal proposals. Paul Hoffman supported this approach.
Guidance on Objecting to Removals: Mikolai Gütschow asked whether participants should voice support for keeping features on the list. Paul Hoffman advised that if a participant has a strong, active use case that would be negatively affected by a feature's removal, they should explicitly state their case on the list. If it is merely a "nice-to-have" feature, participants do not need to actively defend it unless they feel strongly.
ABNF and Next Steps: Once the feature set is finalized and trimmed, the working group will reopen discussions on the ABNF. Joe Hildebrand noted that some minor ABNF tweaks will be necessary once the final feature set is established.

Decisions and Action Items

Procedural Agreement: Proposals to remove features from draft-ietf-cbor-edn-literals must be submitted to the mailing list as individual, dedicated threads per feature.
Action Item: Joe Hildebrand to submit separate threads regarding the removal of the ellipsis tag and the ellipsis feature in draft-ietf-cbor-edn-literals.
Action Item: Paul Hoffman, Christian Amsüss, and Barry Leiba to coordinate and align on mailing list guidelines regarding debates over feature removals.
Action Item: Paul Hoffman to post the summary of today's meeting to the IETF notes.

Next Steps

The Working Group Last Call for draft-ietf-cbor-serialization will continue on the mailing list.
The next CBOR Working Group interim meeting is scheduled to take place in two weeks.

Automatic IETF Minutes