* Added the `--ignore` flag to **validate**. [4385](https://github.com/demisto/demisto-sdk/pull/4385)
* Added validation GR106, to ensure every modified test playbook is used by at least one content item. [4446](https://github.com/demisto/demisto-sdk/pull/4446)
* Added a new **pre-commit** hook to prevent Python files from disabling `mypy` checks in the file level. [4405](https://github.com/demisto/demisto-sdk/pull/4405)
* Added a new optional field, `marketplaces`, in the release notes config (e.g. `1_2_3.json`). Use it to choose marketplaces where breaking changes apply. When a list is not provided, the default is all marketplaces. Supports aggregated release notes and retroactive editing. [4483](https://github.com/demisto/demisto-sdk/pull/4483)
* Added validation PB127 that verifies default keys exist where marketplace suffix keys exist in playbooks. (e.g. using `description:xsoar` now requires `description`). [4401](https://github.com/demisto/demisto-sdk/pull/4401)
* Modified the ***unify*** and ***prepare-content*** commands to add a `demisto.debug` logging of the pack name and version, in Python files. [4437](https://github.com/demisto/demisto-sdk/pull/4437)
* Fixed an issue where PA102 failed when on valid modeling rules. [4497](https://github.com/demisto/demisto-sdk/pull/4497)
* Fixed an issue where reusing the **content graph** after a long period of inactivity resulted in a 409 error. [4495](https://github.com/demisto/demisto-sdk/pull/4495)
* Added a *support* attribute to all content items in the **content graph**. [4430](https://github.com/demisto/demisto-sdk/pull/4430)
* Locked the nltk version to 3.8.1, since 3.8.2 was surprisingly removed from PyPI. No effect on demisto-SDK users. [4496](https://github.com/demisto/demisto-sdk/pull/4496)