Web Content Accesibility Guidelines
W3C Standard 6, Guideline 4 - Clarify natural language usage
This section delt with the use of languages in webpages. There are many different coutries around the world who make webpages and each need to be aware of alternate ways people view their page. With so many different ways people access each page, web developers need to make sure the alternate methods know what the natural language of the page is. The braile readers, speech synthesizers, and other methods people use, need to be aware what language is the main natural language.
Some of the first things these alternative readers look at is the language attributes in the top of the markup code. It is not completely necessary to label it, but it is really a good idea to make your site more accessible. A priority one accessibility issue is when different languages are used in the main content. When someone is changing the natural language, either for a little bit or for the rest of the document, the developer must show the language it is changing to. If a braile reader is reading the content in english and suddenly comes to a couple spanish words, the braille reader may not know how to read the change. For examples such as these, developers need to show when there are changes to the natural language of the page.
It was hard to find a couple sites to compare to each other, but I found a few that used these concepts well. www.bahn.de is an example where they use different attributes to show the language they move or make the page to display in. It doesn't effectively show and use the correct language attribute. http://punto-informatico.it is a great example of an effective use of the language attribute.
