# Freeze exceptions This page outlines some of the common scenarios where freeze exceptions might be wanted. You should read this page before you [Request a Freeze exception](https://documentation.ubuntu.com/project/release-team/request-a-freeze-exception.md#request-a-freeze-exception). ## Feature Freeze exceptions Exceptions to the [Feature Freeze](https://documentation.ubuntu.com/project/release-team/freezes.md#feature-freeze) process must be approved by the Release Team for all packages in the Archive (i.e. `main`, `restricted`, `universe` and `multiverse`). Exceptions should be granted if the upload: * Contributes to high-priority feature goals for the release * Is warranted due to other exceptional circumstances, as judged by the release managers. ### ABI/API compatibility ABI/API compatibility is a special case of a feature. If a library breaks backward compatibility (i.e. changes existing API/ABI and introduces a new [SONAME](https://www.netfort.gr.jp/~dancer/column/libpkg-guide/libpkg-guide.html#sonameapiabi), then this **always** needs approval from the Release Team, since all reverse dependencies need to be adjusted and rebuilt. ## User Interface Freeze exceptions [User Interface Freeze](https://documentation.ubuntu.com/project/release-team/freezes.md#user-interface-freeze) exception request bugs need a justification for why the User Interface (UI) needs to be changed at that point, and give a rationale as to why the benefits of it are worth breaking existing documentation and translations. Refer to the [Request UI Freeze exception](https://documentation.ubuntu.com/project/release-team/request-a-freeze-exception.md#request-ui-freeze-exception) section for additional instructions for your request bug. ## Final Freeze exceptions During the Final Freeze period, extreme caution is exercised when considering exceptions, as a regression could cause a deadline to be missed, or a build to receive less testing than desired. A request for an exception must demonstrate strong rationale and minimal risk for the update to be considered. Refer to the [Request Final Freeze exception](https://documentation.ubuntu.com/project/release-team/request-a-freeze-exception.md#request-final-freeze-exception) section for additional instructions for your request bug. ### Exceptions for universe/multiverse The Freeze Exception process is the same for `universe`/`multiverse` as for `main`/`restricted`, except during the last week of development before the release. During that time, all uploads need to get approved by the Release Team. The instructions for request bugs for `universe` and `multiverse` are the same as those for Final Freeze exceptions. Refer to the [Request Final Freeze exception](https://documentation.ubuntu.com/project/release-team/request-a-freeze-exception.md#request-final-freeze-exception) section for details.