Written by
torleik
For umbraco versions:
umbraco3.0How-to
How to create multilingual sites with only a single navigation-tree,
> using 'tabbed translation' and the dictionary.
Define the languages you want to use. (You can easily add more later) This is done in the Umbraco client "Settings", under Languages.
You can use the primary languages or languages with variety subtag as you please (e.g. you can use English with code en or English (USA) with code en-US. ) Whichever you choose, just do it everywhere a language-code string is used.

Example: I have chosen 3 languages without the variety subtag.
Decide which lan guage is the initial language (the “default” as you may.) I choose English in this case. You may also choose not to have an initial language.