Daniel, Sorry for the delay in the response. This is a very useful adendum. Only one comment...
Only one AS announces an inter-AS network externally. The other ASes connected to the inter-AS network will probably carry this network in their internal routing for redundancy but will not announce it to other ASes.
In exceptional cases more than one AS may need to originate external routing information about the inter-AS network, This kind of routing setup cannot be described within the framework of ripe-81 and is generally discouraged. Tools using a ripe-81 type registry could take heuristic hints from the ias-int attributes when they encounter such situa- tions.
Does this mean that if ANS or Merit announces the FixW FDDI, Barrnet and NASA can't add a pair of routers only peering with each other on the ring? Alternet and PSI at College Park are are another example, but I'm not sure who would "own" that network. (no side discussions on this please - redirect to alt.bizarre.politics.gix or /dev/null :). I think that things like this have been done (and are being done) due to a rather low limit on the number of peers some routers can support (not the ENSS of course :). You may want to allow each AS to announce it's own routers for the DMZ/FIX/NAP/GIX. BTW - We use the term "shared network", but out of context it makes little sense so your term "inter-AS network" seems like a good choice. Curtis