CSS Display says in Box Generation: the none and contents keywords:

Elements with either of these values do not have inner or outer display types, because they don’t generate any boxes at all.

However, in Automatic Box Type Transformations,

Some layout effects require blockification or inlinification of the box type, which sets the box’s outer display type, if it is not none or contents, to block or inline (respectively).

Which is it, do elements with display: contents or display: none have an outer display type with that value, or do they have no outer display types?