# 12\. Document Changelog

For a summary of changes to the Compatibility Definition in this release:

*   [Document changelog](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/?pretty=full&no-merges)


For a summary of changes to individuals sections:

1.   [Introduction](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/1_introduction?pretty=full&no-merges)
1.   [Device Types](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/2_device_types?pretty=full&no-merges)
1.   [Software](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/3_software?pretty=full&no-merges)
1.   [Application Packaging](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/4_application-packaging?pretty=full&no-merges)
1.   [Multimedia](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/5_multimedia?pretty=full&no-merges)
1.   [Developer Tools and Options](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/6_dev-tools-and-options?pretty=full&no-merges)
1.   [Hardware Compatibility](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/7_hardware-compatibility?pretty=full&no-merges)
1.   [Performance and Power](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/8_performance-and-power?pretty=full&no-merges)
1.   [Security Model](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/9_security-model?pretty=full&no-merges)
1.   [Software Compatibility Testing](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/10_software-compatibility-testing?pretty=full&no-merges)
1.   [Updatable Software](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/11_updatable-software?pretty=full&no-merges)
1.   [Document Changelog](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/12_document-changelog?pretty=full&no-merges)
1.   [Contact Us](https://android.googlesource.com/platform/compatibility/cdd/+log/CURRENT_BRANCH/13_contact-us?pretty=full&no-merges)

## 12.1\. Changelog Viewing Tips

Changes are marked as follows:

*   **CDD** <br>Substantive changes to the compatibility requirements.

*   **Docs** <br>Cosmetic or build related changes.

For best viewing, append the `pretty=full` and `no-merges` URL parameters to your
changelog URLs.