Where Can I Give Feedback on Ubuntu?
where to report improvements for some applications that have features which can be enhanced. Current behavior of such a feature should be working exactly as intended.
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Many programs maintain their own bug tracker database, and these are generally the best places for not just feature requests but also bug reports. Many are documented at launchpad: https://bugs.launchpad.net/bugs/bugtrackers , but use your google-fu to find others.