Example: https://meta.wikimedia.org/wiki/Special:CentralAuth?target=Matěj+Suchánek&uselang=cs
Code: https://gerrit.wikimedia.org/g/mediawiki/extensions/CentralAuth/+/30218fe68d2f74a342b43469c9536c4f81fa1e57/includes/specials/SpecialCentralAuth.php#656
In Czech, the "comma separator" is a non-breaking space. But the tooltip will show it as individual characters instead.