The vertical colon in traditional Chinese
tanukihee tanukihee tanukihee tanukihee tanukihee Sorry for the late reply.
The vertical colons and semicolons in traditional Chinese should be vertically arranged
In UTR#50, fullwidth colon (U+FF1A) and semicolon (U+FF1B) are both marked with "Tr", which means "use the vertical variant if possible, but rotate 90 degrees if not". This is why LuaTeX-ja rotates fullwidth colon and semicolon.
I added the exceptional table in ltj-jfont.lua at the commit a80dbd1. If there are other characters that should not be rotate, please let me know.
tanukihee Thank you for your reply. I haven't found other punctuations that should not be rotated. The ticket could be closed.
It is because the vertical semicolon is "undefined" in vertical Japanese that the managements of semicolons are different in luatexja and platex (and MS Word)?
tanukihee 
Fork
The vertical colons and semicolons in traditional Chinese should be vertically arranged like simplified Chinese or two dots leader instead of horizontal arranged like Japanese. (I know Japanese do not use colons and semicolons in vertical writing mode but in fact the managements of semicolons are different in luatexja and platex. platex will arrange the semicolons vertically like MS Word but I don't know what is "more" correct)
Codes for luatexja:
\documentclass{ltjtarticle} \usepackage[match]{luatexja-fontspec} \usepackage{lua-visual-debug} \newjfontfamily\cn{Source Han Serif SC}[Language=Chinese Simplified, TateFeatures={JFM=zh_CN/{vert,quanjiao}}] \newjfontfamily\tw{Source Han Serif TC}[Language=Chinese Traditional, TateFeatures={JFM=zh_TW/{vert,quanjiao}}] \newjfontfamily\jp{Source Han Serif}[Language=Japanese, TateFeatures={JFM=ujisv}] \begin{document} {\cn あ：ア；漢} {\tw あ：ア；漢} {\jp あ：ア；漢} \end{document}Codes for platex
\documentclass{tarticle} \begin{document} あ：ア；漢 \end{document}