Durable record: bound to the owning session id and validated at the fold (orphan-SID shape, temp path inside the host temp root) — a fork's copied parent record no longer provisions the child, and a tampered record fails loud. Private temp dir: random unguessable name persisted in the record, created exclusively (pre-existing entries and reparse points fail EEXIST). Persistence: a fresh provision kicks an immediate flush (no write-behind debounce), narrowing the crash window to the flush latency — documented as the one self-healing gap. Runner-failure rules: exit-gated on 127 so a confined command that prints the signature on a non-127 exit is never misclassified. Spawn: AssignProcessToJobObject failure terminates the suspended child (no hanging orphans). SandboxExecutionPolicy.sessionId is the branded SessionId. Boundary docs: qualifying clause on the absolutist sentences, NULL-DACL Known Limitation, 'full' scoped to the supported NTFS surface, CLM gate comment.