Hi there, I'm attempting to use intrusive associative containers, but it's essential to the application that as I add "equivalent" objects to the multiset that their order is maintained, ie. that the sort is stable. I'm looking at using avl_multiset for its fast retrieve times. I ran an experiment several times over where I added 1000 entries of random numbers from 0-9 that also contained ordering information to a multiset, and that ordering information wound up being preserved, even when I removed some items and added new ones to the initial tree. So that looks promising. If someone were able to confirm the results of my experiment it would be better, though. Best would be documentation that lists which multiset implementations are stable and which aren't, but I can't find such a thing in the docs. Thanks, Dan.