I'm working on an onscreen keyboard for a kiosk-type application where the user can type in their email address using that keyboard.
We will have a 'more symbols' type button to toggle the keyboard state that will show all available special characters separately, but want to provide the most common special characters up-front to make them more discoverable and less annoying to use.
Here's the current layout.
Current email standards according to Wikipedia allow these special characters overall:
However, that's a bit overkill to provide on the initial screen so we've gone with just:
We do have space for one or two more that may be useful, but I can't find any statistics as to the most common special characters used.
Has anyone done any research into this that they can share? Are these 3 options sufficient, or would we benefit more people by adding one or two others to the main keyboard?