No, you don't need to know any special language, what I mean is hoping miniBB could handle Unicode coding correctly, a lot of BBS, guestbook or other text related php (or Perl...) application can handle Unicode naturally, eventhough maybe they are not intended to do so originally.
The problem is not due to encoding setting, not because the users sake. I'm testing miniBB, not used yet. I'm using VBB and invboard in different sites right now, I used UBB and LeoBB also before, they are all OK.
I believe after you rewriting the fuzzy wrapText and keep the Double Byte in mind, the problem will gone.
Anyway, I like your guys, your miniBB is free, I can not ask more, this is only a suggestion for your reference.
miniBB is great, thank you for your answer.