Perhaps (probably) naively, it seems to me that DPA would have been a useful BGP attribute. Can anyone shed light on why this RFC never moved beyond draft status? I cannot find much information on this other than IETF's data tracker (
https://datatracker.ietf.org/doc/draft-ietf-idr-bgp-dpa/) and RFC6938 (which implies DPA was in use, but then was deprecated).