- {language: subformats}. "subformats" is a list sorted from
- lower to higher preference, each element is a dictionary
- with the "ext" entry and one of:
+ {tag: subformats}. "tag" is usually a language code, and
+ "subformats" is a list sorted from lower to higher
+ preference, each element is a dictionary with the "ext"
+ entry and one of: