The candidate set is:

Any element except input, button or select that has a role attribute with the value:

radio
checkbox
slider
combobox
textbox
button

The test logic is any element listed above that does not match the following criteria would be listed as a failure:
If the element has a text node that has a value with a length greater than 1
If the element has an aria-label
if the element has an aria-labelledby attribute that references a valid ID on the page