I'm not sure why, but when seeing the properties of a custom folder in a created PST data file, I see:
The Inbox folder having as a description as :
退ꢐ鑓i駘㡩詧뭩趉땩趓䝩駙兩贶坩駙i
Another one had:
退邐䬰昉䯠昉䩼昉

I'm not sure why, but when seeing the properties of a custom folder in a created PST data file, I see:
The Inbox folder having as a description as :
退ꢐ鑓i駘㡩詧뭩趉땩趓䝩駙兩贶坩駙i
Another one had:
退邐䬰昉䯠昉䩼昉

Here's output from my Alt KeyCode Finder script for your string:
Ch Unicode Alt? CP IME Alt Alt0 IME 0405/cs-CZ; CP852; ANSI 1250
退 U+9000 36864 …0… CJK Ideograph
ꢐ U+A890 43152 …144… Saurashtra Letter Oo
鑓 U+9453 37971 …83… CJK Ideograph
i U+0069 105 …105… 105 0105 Latin Small Letter I
駘 U+99D8 39384 …216… CJK Ideograph
㡩 U+3869 14441 …105… CJK Ideograph Extension A
詧 U+8A67 35431 …103… CJK Ideograph
□ U+BB69 47977 …105… Hangul Syllable Mieum Weo Thieuth
趉 U+8D89 36233 …137… CJK Ideograph
□ U+B569 46441 …105… Hangul Syllable Ssangtikeut Ya Kiyeok
趓 U+8D93 36243 …147… CJK Ideograph
䝩 U+4769 18281 …105… CJK Ideograph Extension A
駙 U+99D9 39385 …217… CJK Ideograph
兩 U+5169 20841 …105… CJK Ideograph
贶 U+8D36 36150 …54… CJK Ideograph
坩 U+5769 22377 …105… CJK Ideograph
駙 U+99D9 39385 …217… CJK Ideograph
i U+0069 105 …105… 105 0105 Latin Small Letter I
I guess that at least all Hangul characters as well as Saurashtra and Latin letters are simply truncated Unicode from CJK Unified Ideographs Extension B to Basic Multilingual Plane codepoints as follows:
ꢐ U+A890 <- U+2A890 i U+0069 <- U+20069 □ U+BB69 <- U+2BB69 (character is properly rendered at link)□ U+B569 <- U+2B569 Your string might be as follows 退鑓駘㡩詧趉趓䝩駙兩贶坩駙 but I can't guarantee that above list contains all such truncation.
Note that rendered □ U+25A1 White Square is simply a replacement character…