Code is supposed to be exact and "as-is". Sometimes, showing two spaces is important. In a comment, it is not possible to show code
with multiple spaces. This became apparent in this answer (see comments).
EDIT: apparently this bug is larger then I thought:
multiple spaces here are neither preserved in normal question text. Pity (though I couldn't find this reported before, I'd assume it is).
Workaround: use Alt+0160 (windows), or U+00A0 (Unicode NBSP), as I did in the example above.