__bytes__, __trunc__, and __float__ returning instances of subclasses of
bytes, int, and float to subclasses of bytes, int, and float correspondingly.

__bytes__, __trunc__, and __float__ returning instances of subclasses of
bytes, int, and float to subclasses of bytes, int, and float correspondingly.

__bytes__, __trunc__, and __float__ returning instances of subclasses of
bytes, int, and float to subclasses of bytes, int, and float correspondingly.

"text", "tail" and "attrib".  Original patch by Santoso Wijaya.

invalid data including tuple instructions.

invalid data including tuple instructions.

invalid data including tuple instructions.

No charset parameter is standardized for this Content-Type value. Also
clarify that urlencode() outputs ASCII.