From: Antoine Pitrou
- a "branch" usually means a "named branch": a set of changesets bearing the same label (e.g. "default"); that label is freely chosen by the committer at any point, and enforces no topological characteristic
There are *some* topological restrictions, because hg won't let you assign a branch name that's been used before to a node unless one of its parents has that name. So you can't create two disconnected subgraphs whose nodes have the same branch name.