Subjects follow the placement tree, so a grant on a folder covers the documents moved into it later and stops covering the ones moved out. A delegated grant's subject must be inside the delegator's subject: the same node or a descendant, or the same group. The space root as a subject covers the whole space, which is what the roadmap's "a writer of a space is a writer of the whole space" means; narrower subjects remain available because capabilities now target stable nodes instead of paths, so a move cannot change what a grant covers.

A Capability has a path scope, recursive by segment. Path scopes are being discontinued because moving a document changes its authority. Node subjects restore granular sharing without that problem.