It is not permitted to combine generic and specific UseTypes (e.g. Stream and InteractiveStream) in a single Deal.

It is not permitted to signal all specific sub-UseTypes (e.g. all *Stream UseTypes) defined by DDEX in a single Deal. In such cases the generic UseType shall be used.

At the same time, message senders are encouraged to only send multiple specific sub-UseTypes if really necessary. The preferred method is to use the generic UseType instead.