Session Date/Time: 09 Mar 2022 15:00

CBOR

Summary

This meeting focused on the submission of the file-magic document to the IESG, a call for feedback on PACT implementations, and an extensive discussion on developing a more readable diagnostic notation for PACT-encoded data. The group also briefly touched upon potential new work, including applying CDDL to CSVs and the ongoing development of CDDL2.

Key Discussion Points

File Magic Document Status:
- The updated shepherd write-up has been uploaded for the file-magic document.
- A minor point was raised regarding the use of "CBOR objects" in the abstract, with a suggestion to prefer "CBOR data items" for clarity, especially for those familiar with JSON terminology. This is the only instance of the term in the abstract.
- The IESG will review the document. The AD noted that the Last Call might be longer due to the upcoming IETF meeting schedule, but there is no particular urgency for earlier submission.
PACT Implementation and Diagnostic Notation:
- Carsten Bormann requested feedback on PACT implementations, noting that his own implementation (part of the CBOR diagnostic package) is still undergoing refinement and its compressor is currently "pedestrian."
- Michael Schaad mentioned plans to implement PACT for CoRAL.
- A significant discussion ensued regarding the need for an improved diagnostic notation for PACT, given its use of numeric tags which can hinder readability.
- Ideas for improving readability included:
  - Special notation for references, showing the actual index.
  - Diagnostic tools providing more information, such as the unpacked form with "breadcrumbs" to indicate where data was packed from.
  - A CURIE-like notation (e.g., dict:entry#50) for dictionary entries, providing a compact, human-readable name that is neither the numeric identifier nor the full expanded form.
- A strong sense of those present indicated that such a diagnostic notation is a high priority for effectively working with PACT.
Other Potential Work and Document Status:
- CDDL for CSVs: Carsten Bormann presented an initiative to use CDDL for describing the data model of CSV columns, addressing a lack of formal description techniques in the open data community. This is seen as an application of existing CDDL, not a new specification for CBOR itself, and was prompted by a real-world need to define a CSV format.
- CDDL2: This is a brewing topic, currently without a dedicated Internet Draft, though aspects are covered in the freezer document. The module mechanism (combining multiple CDDL specifications) is a key area of ongoing thought.
- Working Group Documents: With file-magic moving to IESG, packed will be the only active working group document. notable-tags is also in the pipeline, but not urgent.
- Language Tags: There is an urgent discussion around language-tags regarding implementations not checking tag lengths and whether to consider a language-text-direction tag or simply pick another tag for relevant use cases.

Decisions and Action Items

Decision: The file-magic document will be submitted to the IESG for review. The shepherd write-up will note the intention to change "CBOR objects" in the abstract to "CBOR data items" and address IANA considerations.
Action Item (Carsten Bormann): Continue developing and refining the PACT diagnostic notation to enhance readability and aid debugging.
Action Item (Working Group): Community members are encouraged to provide feedback and contribute to PACT implementations.

Next Steps

Monitor the IESG review process for file-magic.
Continue discussions and potential development of a concrete proposal for PACT diagnostic notation.
Further explore concepts and formalization for CDDL2, particularly the module mechanism.
Address the outstanding issues regarding language-tags, including implementation checks for tag length and potential new tag definitions.