This allows content creators to select multiple options. The display methods for this multi-select field are as a checkbox input or select field. Dragging the choice boxes will re-arrange those options for the content creator.
Whether multi-choice is allowed is controlled using a new boolean property multiple.
The new display type is checkbox.
The values of the field if multiple is set to true are returned as items in an array. Since this is a new feature on the existing Choice field, multiple is set to false by default.
This change is now live to all accounts.