In many cases, these applications may not be things you see as important when first developing your content, but they are typically very easy to add during creation, but much more problematic to retrofit when the need arises.

In addition, some of the applications for language tagging are still in the early stages of development, or lacking, but it is best to add language information to your content now in order to be able to reap the benefits when the technology matures.

This may change in the future, particularly as the larger search engines take an increasing interest in language. However, we are currently faced with a circular problem. People who don't see the applications of language information do not provide information about their content. Language-related applications are slow to be deployed until this information is widely applied to content. This cycle can be broken by content authors taking steps to declare language information.

As we already said, this is usually very easy to do right now, and carries no penalties.