Control characters, DEL, the C1 controls, U+2028, U+2029, U+FEFF, U+FFFE and U+FFFF were written as they are, where the reader refused them, folded U+0085, U+2028 and U+2029 to a space, or dropped a leading U+FEFF. They are now written as the escape that stands for each, in a quoted string, and never plain or in a literal block.
