Comment from the i18n review of:
Location in reviewed document:
The term 'primary' is used here in a different way than currently used in i18n documents. We use 'primary language' to meanthe intended audience of the document - as specified in the HTTP header or the meta statement. Our equivalent for your term 'primary language' wouldbe 'default text-processing language', based on the associated explanations. This is what is expressed via the language attribute(s) on the html element. (Note that we are currently considering options for replacing the term 'primary language' with something less ambiguous and moreaccurate.)
For a summary of our current usage see
We believe that what is necessary for accessibility is identification of the text-processing language - ie. so that text-to-speech systems know what language they are dealing with.
We suggest that you say "The natural language or languages of the Web unit..."
We have revised our terminology to "default human language". We have changed the use of this term in both the guidelines and techniques.