WTF-8

WTF-8 (Wobbly Transformation Format − 8-bit) is an extension of UTF-8 that can also encode stray "surrogate" code units, as may occur in ill-formed UTF-16.

It is not intended to be a standard format for data interchange. But despite its name, it is not a joke format. It can be useful for some internal processes.

Links

 * The WTF-8 encoding