Upgrading the Bitbucket Server Integration plugin from 3.5.0 to 3.6.0 caused the "Manage Old Data" page of Jenkins to show notices about "branchName" in several builds. This seems to have been caused by https://github.com/jenkinsci/atlassian-bitbucket-server-integration-plugin/pull/403 (for JENKINS-71289), which modified BitbucketRevisionAction.java to replace private final String branchName with private final String refName.

Please document in the 3.6.0 release notes of the plugin:

• That Jenkins will show "branchName" as old data.
• Whether there will be problems if a Jenkins administrator downgrades the plugin back to 3.5.0 or lower, after some builds have been done with 3.6.0 or higher.

Please also consider whether hpi.compatibleSinceVersion should be set as described in Mark a new plugin version as incompatible with older versions.