why these numbers?
255 = U+FF are the so-called Fullwidth Latin Characters (http://www.unicode.org/charts/PDF/UFF00.pdf) they are "A" "B" "C" etc. but having the width of a Chinese character (roughly "A ", "B ", "C "). Since they look rather ugly in non-CJK texts and they have to match the width of the Chinese characters in the font, they are only in CJK fonts.
32 = U+20 are general punctuation. I don't see a reason for those. http://www.unicode.org/charts/PDF/U2000.pdf
37 = U+25 are box drawing characters - no idea why those should be included. http://www.unicode.org/charts/PDF/U2500.pdf
38 = U+26 are miscanllaneous symbols - no idea why those should be included. http://www.unicode.org/charts/PDF/U2600.pdf
For fast input of chinese characters i use "NJSTAR Chinese Wordprocessor". It has a menu entry "Symbols Input" -> "Punctuation". Thats why i thought all these symbols can appear in chinese texts. The only necessary entry is the entry for 255. Greetings and thanks again Lutz