The matrix are on the back of the official Netease wow cards. It's the big scratching grid.
To activate the security :
1. log into your www.battlnet.com.cn account
2. click 修改安全选项
3. Click the icon who looks like a gamecard
4. in the 1st field enter the 15 digits number who is on the back of your card, the one who is just over the grid in the left.
then enter the 3 combinations of numbers found on your matrix.
5. click the big button. GG done.
6. do not ever lose the card
Now when you log into the game after entering your login and pass, you'll be asked to input a combination of numbers found on your matrix. This prevent hackers to access your account.
You'll also need to input numbers when you try to login into your battlenet.com.cn account, or when doing operations like password change etc.
With this your account is 100% secure
When you log on a realm type "/join english
" to get in touch with the community members.
WoW English/Chinese glossary
(2000+ translated words) found on wow-in-chinese.jfs-web.chEnglish speakers are consolidating on the same realm for Cataclysm check this thread