this data identifies what type of player or equipment is needed so that you can “view, play, run, etc., the content of a resource”; a closed list of terms is used to identify whether the media device needed to access the content of the resource is an audio player or a video player or a computer, etc.
data for this element must be Recorded from a vocabulary (Closed): the term(s) must be appropriate for the resource, even if they are not from the official list of terms
but be sure to check the resource carefully, if the data for the element is Core, or if the data is important for differentiating the resource from a similar resource