Assume you want to store the locale of user preference in database, which value you will use?

en_US or en-US

They are two standards, but which one you prefer to use as part of your own application?

Updated: Is seems many web sites use dash instead of underscore, e.g.

http://zh.wikipedia.org/zh-tw http://www.google.com.hk/search?hl=zh-TW

Edit
Report