obox can and often supports both inline forms of autocomplete in combination with having a popup element. 
Authors can use `aria-autocomplete="both"`. 
The inline completion string is visually highlighted and has a selected state.

The `aria-autocomplete` property is _not intended to indicate_ the presence of a completion suggestion, 
and authors _should not_ dynamically change its value in order to communicate the presence of a suggestion. 
When a text entry element has `aria-autocomplete` set to `"list"` 