FEATURE IDEA: Enable "autocomplete" on "tab" while typing in an existing tag name

mag998

It would be very beneficial to have an "autocomplete" when hitting the "tab" key while typing in an existing tag name instead of having to type in the entire name. RIght now you have to hit "tab" multiple times in order to find the right tag and that's not feasible when you have 50+ tags. Alternatively, you have to use the mouse to select the correct tag. This should be implemented almost exactly the same way that you can hit the "@"-key in a sticky comment and then select the correct user.