BuddyPress.org

@jianzhi you’re welcome. Happy BuddyPress-ing 🙂

@jianzhi Manual edit at this time 🙂
Edit your first post, add [Resolved] to front of title. For your own forums, you can install a cool plugin https://wordpress.org/plugins/buddy-bbpress-support-topic/

@jianzhi You’re in luck. Check out http://buddydev.com/buddypress/making-wordpress-seo-plugin-compatible-with-buddypress/

@jianzhi could be a theme issue. What theme are you using? Change to Twenty Twelve theme and check if issue is resolved.

@jianzhi
I needed this a while back for a bunch of existing users, so ran up a simple quick script to do this, wouldn’t run it on a production site but worked in my test environment for my purpose, you can copy and run if it helps:
https://github.com/hnla/force-show-bp-users/blob/master/force-show-bp-users.php

@jianzhi There are BuddyPress websites in Arabic and Chinese among others, with @ mentions working in their sites.

What language are you using for your site? What’s the character encoding in your site, i.e., database? http://radoff.com/blog/2009/12/03/chinese-characters-in-wordpress/

@jianzhi
You will probably want to view the info here:
https://codex.buddypress.org/developer/customizing/customizing-labels-messages-and-urls/
here:
https://codex.buddypress.org/user/translations/
And get the language file you need here:
https://translate.wordpress.org/projects/buddypress/dev