For what it’s worth, with IDNs you’re still going to do a kind of case folding using stringprep before doing the query, and that isn’t really better than the ta

For what it’s worth, with IDNs you’re still going to do a kind of case folding using stringprep before doing the query, and that isn’t really better than the table GP linked. ASCII-only case-insensitive matching is indeed a thing, but it’s usually mutually exclusive with (non-programmer) user-entered data.