The Checkbox form item is intended to enable or disable a certain option.
A checkbox can have two or three states.
Fig. 49. A checkbox
If a checkbox in a table column or a form is not available for editing, it appears shaded.
To toggle the value of a checkbox, click it. If you use the keyboard, first activate it using Tab or Shift + Tab, and then press the Spacebar.
If a checkbox has two states, you can also use the Plus Sign and Minus Sign keys to toggle it.
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