Take the 2-minute tour ×  What zero-width characters exist in
UTF-8 that are not treated as spaces1? I am particularly
interested in those which glyphs that do not render on major
browsers: the not-found rectangle should never be shown.  There
are many web services that order user entered data
alphabetically (eg. Gmail's labels). I would like to use those
invisible characters to enforce custom ordering.  1 Treated as
spaces: not removed by commonly used implementations of trim and
similar. With the gmail example, U+202F (Narrow no-break space)
is trimmed.  Edit: Only one invisible character should suffice.
After all, they may be repeated without having an effect on the
visual representation (assuming a lower code ascii text
follows):  [char]Z on first position [char][char]B on second
position [char][char][char]C on third position  Unfortunately,
all characters I could think of are either trimmed right away or
ignored by sort functions.  Edit: I've browsed through all UTF-8
characters that seemed zero width /