Among other things, we are using JIRA for the tracking of support requests. Issues are created via email, notfications are sent out to the reporter and all watchers (usually at the customer end) whenever a new comment is made. Reporter and Watcher contribute to the issue by replying to those notifications. The JIRA Web Interface is not used by most users on the customer side.

In this setting, it is of interest to know which notifications an individual user actually got. In the change history, all relevant information is available - but not when a user was added or removed from the watcher list.