Invalid unicode characters in Myanmar

[williamlow]

Looking at Yangon in Myanmar there are what appear to be large numbers of unicode character ☐ (U+2610), which I understand to be failed representations of Burmese language characters. As a side note, the use and state of Burmese language fonts has always been a bit confusing (I think a non-unicode version, Zawgyi, remains dominant).

[williamlow]

Example: http://maps.stamen.com/toner/#16/16.7754/96.1616