I just spent a very long time trying to write thoughtful Unicode suggestions for someone here:Color Coding Assignment Groups in Modules
However, when my comment posted, it silently ate several of the Unicode symbols I used without throwing any warning that it would do so. (Specifically U+1F514 BELL, )
Had I not read my comment after posting it, I would have had no idea that it happened, because no error message was thrown, it was just silently eaten.
Not cool. Symbols carry meaning, and silently eating them can change the meaning of a post without tipping off the poster that their meaning won't come through.
If there is some technical or security reason why such symbols must be eaten, throw an error and let the poster revise within the allowed bounds.
Otherwise, let them through, since there are plenty of good reasons to use them (I see my post as an example of that).
(Yes, I know this really goes in Meta Community Group, but it won't let me post there directly so I have to hope someone else moves it.)