Volity uses the DC vocabulary for some metadata in UI files -- common terms like title, creator, description and creation date.
(Volity-specific metadata such as version numbers are not described via DC, but rather by Volity-specific terms.)
All DC element types are legal, but Volity pays special attention to:
For human-readable text in a particular language (such as title and description elements), you can add a xml:lang
attribute to specify what language the element is in. It is reasonable to use multiple elements with different language attributes.
See the example on the metadata page.