Chinese

http://www.iana.org/assignment[...]uage-subtag-registry^[link1] defines the following

zh-Hans - simplified Chinese
zh-Hans-CN - PRC Mainland Chinese in simplified script
zh-Hans-HK - Hong Kong Chinese in simplified script
zh-Hans-MO - Macao Chinese in simplified script
zh-Hans-SG - Singapore Chinese in simplified script
zh-Hans-TW - Taiwan Chinese in simplified script

zh-Hant - traditional Chinese
zh-Hant-CN - PRC Mainland Chinese in traditional script
zh-Hant-HK - Hong Kong Chinese in traditional script
zh-Hant-MO - Macao Chinese in traditional script
zh-Hant-SG - Singapore Chinese in traditional script
zh-Hant-TW - Taiwan Chinese in traditional script

So we need mappings as follows:

zh-tw --> zh-hant-tw
zh-hk --> zh-hant-hk
zh-mo --> zh-hant-mo
zh-cht --> zh-hant

zh-cn --> zh-hans-cn
zh-sg --> zh-hans-sg
zh-chs --> zh-hans

Mandarin Chinese (Simplified Script) 简体中文
Mandarin Chinese (Traditional Script) 正體中文

CooCooWakka

Links

[link1] http://www.iana.org/assignments/language-subtag-registry
[link2] https://sourceforge.net/p/ccwakka/code/HEAD/tree/trunk/coocoowakka/language/schinese-utf/main.php
[link3] https://sourceforge.net/p/ccwakka/code/HEAD/tree/trunk/coocoowakka/language/tchinese-utf/main.php