Checkbox & Radio Group
Checkboxes accumulate, radios exclude — and the requirement is the group's, so it is stated where the role's semantics accept it
Inputs · Forms
Inputs in Forms: 6 designs — Checkbox & Radio Group · File Upload / Dropzone · Select / Combobox · Slider / Range
Designs
File Upload / Dropzone
A dropzone whose native input is present, not hidden — so the keyboard reaches it and a screen reader names it, and the bar is a native element
Select / Combobox
A native list with no JavaScript — the placeholder shows but cannot answer, so the constraint genuinely fails on it
Slider / Range
A native range kept in its own direction — never flipped by a trick, and the visible readout hidden from AT because the control already announces its value
Text Field
Six states of one field — each a real attribute a screen reader can hear, not a class that only colours