ZWNJ (U+200C) not allowed in #tags
taken from irc
I got two questions, I'll leave the questions here and put the web irc to background until someone answers
two) why does the hashtag breaks when there is zero-width non-joiner character? it had made words in some languages break where the character is needed as part of the grammatical spelling -- for example when we write #ساٴينس then the hashtag will just take ساٴين and leave the س ... that ساٴينس is one continuous word that needs the character, ساٴينس and ساٴينس are two different words that cannot be equated with each other
it's U+200C for details https://en.wikipedia.org/wiki/Zero-width_non-joiner