If the stylesheets need to generate text (the names of labels such as “Chapter”, for example), they attempt to do so in the same language as the document. This is determined by finding the nearast in-scope xml:lang attribute from the context where the generated text is required.

The stylesheets can generate text in more than 70 languages, but very few documents use more than a few. To avoid the overhead of loading a great many localizations that will never be used, the stylesheets don’t load them all.

The stylesheets always load the $default-language and will load any additional languages identified in $additional-languages, a space separated list of language identifiers.

If the $additional-languages is the empty sequence, the stylesheets attempt to determine which languages are used in the document and load the appropriate localizations.