[CARD Technical Issue] U flag and Unsolicited CARD

Section 4.2.2 mentions that unsolicited broadcast is possible, why not
multicast? For IPv4, this would require a multicast address,  but for IPv6
it could be done to the All Nodes Multicast address on the link. There is no
broadcast in IPv6, so multicast will be required in that case anyway.

The draft also contains no guidelines about unsolicited. What is the default
intermessage time on broadcast/multicast? What about the port number and
TTL?

Also, I'm not clear about why an unsolicited message needs to be marked. How
would a MN utilize the U flag? How would processing of a solicited v.s.
unsolicited message differ?



            jak