The "global" email notifications settings (Administration -> Settings -> Email notifications) currently allow to specify the following issue updates to be watched by users who have chosen to watch "any events on...":

[ ] Issue updated 
     [x] Note added
     [x] Status updated
     [x] Assignee updated
     [x] Priority updated

We suggest to add "Tracker updated", as we consider it a substantial event for certain people (e.g. a customer willing to know whenever a Bug is changed to a Feature, but don't want to be spammed by issue reassignments). The new 'Issue updated' action notifications would be:

[ ] Issue updated 
     [x] Note added
     [x] Status updated
     [x] Assignee updated
     [x] Priority updated
     [x] Tracker updated

This update would be especially beneficial for "Event notifications":http://www.redmine.org/plugins/event_notifications plugin users, who are able to set these standard notification options also per-user and per-project.

The patch against current trunk (r13520) is attached; if there is anything we should improve, please let us know.

P.S. I've noticed this feature is similar to #16362, where assignee change was added.

(thanks to Sandra Tatarevicova, sponsored by Orchitech Solutions)