Nothing uses well-formed UTF-16. I don’t think I know of a single piece of software or library that uses 16-bit code units that validates them. In practice, “U

Nothing uses well-formed UTF-16. I don’t think I know of a single piece of software or library that uses 16-bit code units that validates them. In practice, “UTF-16” means “potentially-ill-formed UTF-16”. It’s that simple.