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Please have a look at Preferences window in case you'd like to know more about the Preferences... menu in your client.
Feature Design Document
Discussion for future improvements
Relationship to other features
List of features that need to be tested when this feature changes, and why.
- Play it by ear, this could affect several client side features.
- Log out and in - verify you preferences remain.
- Upgrade to a new version of the client - verify you preferences remain.