[rbridge] When would an RBridge say "I don't want layer 2 multicast"?

[Radia Perlman]

There's currently a flag in an LSP for an RBridge to say "don't send me 
layer 2 multicasts that aren't
derived from IP multicasts".

Would this ever be used? Can all layer 2 non-IP-derived multicasts 
really be lumped into the same
bucket and turned on and off as a unit?

It seems safer to me to remove that flag, since maybe there are some 
important layer 2
multicasts? Maybe it's intended as a safety thing, because 
IP-derived-multicasts have
to be explicitly requested (unless you are an IP multicast router), 
whereas the other
layer 2 multicasts would go everywhere?

And if we do have that flag, and someone says "I don't want 
non-IP-derived layer
2 multicasts", does that include ESADI information?

Radia