Jira recently introduced a new rich text section within project versions. Not sure what this field is called as. But it allows you to add additional notes for a release version in rich text format. (Unlike the traditional version description field which is in plain text.)

This is how this section is visible on the UI.

Currently, this is not listed as either a field/object in the API reference 4, or a field available as an expand.

As an app developer, I would like to fetch details of this field via Jira REST APIs so that we can consume that information. In some scenarios, we would also like to update this field via REST APIs.

Please note, the other recent additions to this screen such as Related work, Version driver, and Version approvers are already made available in the REST APIs. Only this rich text section is still not supported.