Making the quick search suggestions accessible means that, when these suggestions are available:
- They are declared as such to screen readers so that the user can know about their existence.
- The user can go through the suggested entries using the keyboard arrow keys, like what is possible on typical search engines such as Qwant and Google.
- Accessible autocomplete: https://haltersweb.github.io/Accessibility/autocomplete.html
- ARIA combo box: https://www.w3.org/TR/wai-aria-practices/examples/combobox/aria1.1pattern/listbox-combo.html