ReadonlycheckedWhether a checkable control is checked — and null for a widget that is
not checkable at all, which is most of them.
Three-valued rather than false-by-default for ARIA's own reason: an
aria-checked of false says "this is a checkbox and it is clear", while
an absent one says "this is not a checkbox". A panel reporting false
would tell a §75 mirror the first when the truth is the second. See
UIWidget.checked.
ReadonlydisabledThis widget refuses interaction (§75's disabled state).
ReadonlyfocusedThis widget holds the focus of its scene root (§75).
ReadonlyhoveredA pointer is over this widget's hit area.
ReadonlypressedA pointer is pressed on this widget.
A widget's interaction state at one instant (§72, §75).
The flags §75 asks a mirror to expose that this tier can actually observe.
expandedstill belongs to a control that does not ship (see UI_STAGED);checkedjoined the record on 2026-08-07 (A-12) whenToggle,Checkbox, andRadioButtonshipped.