Check

An option in a form: a small square key that presses below the plate when chosen, with a tick printed on it.

Checked keys stay down. Space toggles the one that has focus.

• A real checkbox: reached with Tab, toggled with Space, announced as “Dither, checkbox, not checked”.
• Checked shows three ways: the key is lower, the tick is printed, and the input is :checked.
• If the change applies at once, it is a switch; a check is for forms that are saved.