0FD9..0FDA    ; valid                  ;      ; NV8    # 6.0  TIBETAN MARK LEADING MCHAN RTAGS..TIBETAN MARK TRAILING MCHAN RTAGS
0FDB..0FFF    ; disallowed                             # NA   <reserved-0FDB>..<reserved-0FFF>
1000..1021    ; valid                                  # 3.0  MYANMAR LETTER KA..MYANMAR LETTER A
1022          ; valid                                  # 5.1  MYANMAR LETTER SHAN A

and the second value, of type <code>rune</code>, will be the value of
the corresponding code point. If the iteration encounters an invalid
UTF-8 sequence, the second value will be <code>0xFFFD</code>,
the Unicode replacement character, and the next iteration will advance
a single byte in the string.
</li>

<li>
The iteration order over maps is not specified