The original DSR paper described data grams as the most primitive signal thru the net.
It provides no priority information however.
I can imagine that some switches would offer some sort of priority on outgoing links as indicated by a "quality mark" within the routing information.
In fact each switch determines the meaning of its portion of the routing field.
It would be well to establish a standard here but not logically necessary.
It is hard to imaging a standard on meanings of quality marks.
The toll extracted by a switch could well depend on the quality mark.
It would be necessary for guides to deal with the meaning of quality marks, perhaps as empirically determined for each switch as part of their duty to advise travelers on the quality of the switches.
I think that most QoS issues are better handled for circuits rather than data grams