**Session Date/Time:** 06 Mar 2024 15:00

# [CBOR](../wg/cbor.html)

## Summary

The CBOR working group held an interim meeting to discuss the status of various drafts and plan the agenda for IETF 119 in Brisbane. Key discussions included the progress of documents currently in Work Group Last Call, the near completion of the CDDL Modules draft, the use of EDN extension points for external references, and a proposal to structure the IETF 119 meeting with tutorial blocks for newer features. The scheduling of future interim calls was also finalized.

## Key Discussion Points

*   **Document Landscape Overview**: Carsten presented an overview of the active CBOR-related drafts, categorizing them into formal states, CDDL extensions, EDN extensions, core CBOR extensions (tags), and applications.
*   **Work Group Last Call (WGLC) Documents**:
    *   The CBOR Diagnostic Notation (EDN) document is stable.
    *   The CDDL Grammar document received last-minute changes to fix omissions related to simple values (32-255) based on user feedback.
    *   The CDDL Extension Point Control Operators document (including base64 and printf) is also in WGLC.
    *   A poll of those present indicated no immediate questions for discussion on these, but a general call for reviews was made.
*   **CDDL Modules**: This draft is nearing completion but cannot yet be shipped due to an outstanding issue regarding "sockets," which represent incremental additions to choices (e.g., for extension points like `SF`). The objective is to have it ready for the IETF hackathon to test modularized CDDL models using sockets.
*   **EDN Extension Points (E and Ref)**: The discussion covered the use of EDN extension points for constants (E) and external references (Ref).
    *   **E (Constants)**: Designed for models needing numerous constants, especially if defined in other drafts or registries (e.g., GM admin document). It implies a separate CDDL model defining these constants.
    *   **Ref (References)**: Allows pointing to other pieces of EDN, identified by file names or URIs, to include complete examples (e.g., certificates) without embedding them directly. This is about identifying EDN trees, not named constants.
*   **Core CBOR Extensions and Applications**:
    *   Mentioned work on PS Prefix (tags/simple values), Notable Tags (cohering tag info), and Christian's draft on references in table setup.
    *   CBOR applications like DNS CBOR and the CBOR YANG stand draft were briefly noted, with the latter addressing the use of CBOR tag definitions for binary representations in YANG.
*   **IETF 119 Agenda Planning**:
    *   Discussion revolved around dedicating blocks of the IETF 119 meeting to "tutorial-style" content for new features like CDDL Modules and EDN E/Ref.
    *   A sense of those present indicated a preference for placing such tutorial blocks at the beginning of the meeting to maximize attendance and engagement.
*   **Deterministic Serialization**: Drafts on Common Deterministic Encoding (CDE), an application profile, and an informational backgrounder were noted. It was clarified that these are not currently planned for discussion at IETF 119 but may require a dedicated interim meeting. The importance of keeping the CDE specification concise was emphasized, with the informational document providing necessary context.
*   **Interim Meeting Schedule**: Tentative dates for interim calls between IETF 119 and 120 were reviewed.

## Decisions and Action Items

*   **Decision**: The IETF 119 Brisbane agenda will be restructured to include "tutorial-style" presentation blocks for CDDL Modules and EDN Extension Points (E and Ref) at the start of the meeting.
*   **Decision**: Interim working group calls between IETF 119 and IETF 120 will commence on April 17th, maintaining the established cadence of CBOR interims on even weeks, and avoiding the May 1st holiday.
*   **Action Item**: The Chair (Marco) will prepare and upload a draft agenda for IETF 119 based on the meeting's discussion.
*   **Action Item**: Working Group members are strongly encouraged to review and provide feedback on the documents currently in Work Group Last Call, including EDN, CDDL Grammar, and especially `cddl-more-control`.

## Next Steps

*   The Chair will circulate the proposed IETF 119 agenda for review.
*   Working Group members are requested to provide comments on the WGLC drafts.
*   Continued development and testing of the CDDL Modules draft, particularly regarding the "sockets" functionality, in preparation for the IETF hackathon.
*   The first interim call between IETF 119 and 120 is scheduled for April 17th.