check, checkbox, check mark

Use check mark to refer to a mark placed next to an item to show it’s selected.

Use checkbox, not box or check box, to refer to a checkbox in UI. Avoid talking about UI elements. Instead, discuss what the customer needs to do or what they're looking at.

Use select and clear with checkboxes, not turn on and turn off, mark and unmark, check and uncheck, or select and deselect.

See also Describing interactions with UI, Formatting text in instructions