WinRT & XAML - Resource files, but for language, not localization?

Question

Roughly speaking, reading on localization and Visual Studio 2012 C # and XAML for a Windows store application pointed me here: http://msdn.microsoft.com/en-us/library/windows/apps/xaml/Hh965329.aspx

This shows how to create a resource file for, say, en-US and fr-FR, which are both English and French. Shows how to use the resource loader to load it. It’s good to load it automatically using the UID on the Xaml page.

However, my confusion comes to, say, the creation of a Spanish resource file. But I want it to be used for any localization of the Spanish language. If I installed it for mx-ES, what happens if the localization is pe-Es for Peruvian Spanish or es-ES for Spanish-Spanish. Basically, I got a little confused about how I make 1 resource applicable to all English or all French or all Spanish, without being tied to a country and should not make a separate resource file for each combination of countries / languages.

I thought it would be a simple question, but I did not see where anyone else asked him.

Answer 1

Use only the language code for the culture, so ES instead of es-ES.