Concise Binary Object Representation (CBOR, RFC 7049) extends the JavaScript Object Notation (JSON, RFC 8259) data interchange format to include binary data and an extensibility model, using a binary representation format that is easy to parse correctly. It has been picked up by a number of IETF efforts (e.g., CORE, ANIMA GRASP) as a message format. The CBOR working group will update RFC 7049 to deal with existing errata. Security issues and clarifications may be addressed, but changes to the document will ensure backward compatibility for widespread deployed codebases. The resulting document will be targeted at becoming an Internet Standard. Similar to the way ABNF (RFC 5234/7405) can be used to describe the set of valid messages in a text representation, it is useful for protocol specifications to use a description format for the data in CBOR-encoded messages. The Concise Data Definition Language (CDDL) is such a description technique that has already been used in CORE, ANIMA, CDNI, and efforts outside the IETF. CDDL has been published as RFC 8610. While this specification has been completed, several new features were raised during the update process that were not included, in order not to delay publication, and to allow publication in the Standards Track. One example of such a feature is the ability to combine multiple CDDL files together using a mechanism other than manually concatenating them together for processing. The working group will collect these features as well as other features that are raised by users of CDDL, evaluate their utility and add to a second edition of the specification where warranted. The working group will define the approach to further evolving CDDL as a sequence of editions, which might also add further extension points, probably as part of the introduction of the next edition of the CDDL base specification. The body of existing specifications that make use of CDDL is considered precious, and the WG will set out not to damage their value. The working group will evaluate the necessity of providing advice and guidance for developers using CBOR and CDDL. It is currently expected that this would be done using a Wiki of some type. This work would not be expected to be published by the IETF as an RFC. There are a number of additional CBOR tagged types and CBOR related media type specifications that are currently adopted by the working group, are work items in other working groups, or exist as individual submissions. Additionally, there are expected to be other such documents that will come to the attention of the working group. In some cases, the working group will be asked to adopt and publish these proposals. The working group will evaluate such requests individually and decide about adoption and milestones as such requests arise. Proposals that are deemed to be out of scope for the working group, for example because they are too narrow-purpose of a specification, may still be published as individual submissions or in other groups if there is a specific need. The CBOR group will review these proposals on request.