Hi I have the gut feeling that copyAllTo: is not really nice because unclear. The comments are unclear on the "flattening" It is unclear that it flattens the leaves or not. I mean A B x C D y z A copyAllTo: K do we get K B x C D y z or K x y z We got touched by such difference and the message name is not enough intention revealing. I would prefer a message copyAsSuchTo: copyLeavesTo: What do you think? Stef