As I note, some functions of PHP which Moodle are using don't support UTF-8.
I'll take an example with the glossary module. They are the functions handling strings:
- substr ()
- strtoupper ()
In fact, using the functions, some Vietnamese characters could not be displayed properly (more information at http://moodle.org/mod/forum/discuss.php?d=25725)
I dealt with the situation by replacing them by:
- mb_substr ()
As you know, these support UTF-8 and it worked for Vietnamese. I don’t know whether Chinese and Japanese, and other languages have the same problem.
I think we should consider that in the future versions of Moodle so that Moodle can support completely all languages in the world.