WCAG 2.0, PDF/UA and the State of Oklahoma require that the natural language of a document be programmatically defined so that assistive technologies can correctly identify and pronounce text.
If the document is in a single language CommonLook PDF makes it easy to set the natural language via the Document > Set Language menu item. For documents containing multiple languages, choose the predominant language for the document, or else be prepared to set the language individually for each tag!
Of course, documents aren’t always in a single language; many documents contain text in two, three or more languages.
CommonLook PDF makes it easy to ensure that individual tags have a valid correct language setting irrespective of the document’s primary language.
Select the tag containing the content requiring language settings management, then click the Properties tab under the Physical Window to show that tag’s properties. Select the correct language from the drop-down.
For individual words or phrases without a paragraph in a different language, use <Span> tags to contain the second language’s text so you can set it’s properties correctly.