Before releasing a new package, you need to write the release notes in package.xml. The release notes should clearly say what has changed in comparison to the last release, or - when going to the next stablility level, like from beta to stable - list the changes since the last release of the same stability.
You probably want to outline new features, as well as list the bugs which have been fixed. It is important not only to plainly write down the bug numbers, but also the bug titles. People tend to recall words better than remembering the issues associated with a number. The PEAR web interface automatically links structures like "bug #<number>". In case several people fixed patches, the user's handle can be appended to the message.
Bad release notes
- Fixed bug #11495
Good release notes
Changes since the last stable version 1.2.3: - Added foo and bar feature - Blubber is far more efficient Fixed bugs: - Removed deprecated cURL option CURLOPT_MUTE (Bug #13489) [ashnazg] - Changed the license to the New BSD License (Bug #13831) [helgi] Minor issues: - Converted package.xml to version 2.0 - Cleaned up code to (mostly) comply with phpcs