Is the binaryness/textness of a data format a property?

[Martin J. Dürst via Unicode]

On 20/03/2020 23:41, Adam Borowski via Unicode wrote:

> Also, UTF-8 can carry more than Unicode -- for example, U+D800..U+DFFF or
> U+11000..U+7FFFFFFF (or possibly even up to 2³⁶ or 2⁴²), which has its uses
> but is not well-formed Unicode.

This would definitely no longer be UTF-8!   Martin.