A — 0: “Ownership” is asserted but required assets are unspecified. B — 1: Artefacts and rights are listed, but export or redeployment has not been planned. C — 2: Rights, export formats, dependencies and a feasible exit rehearsal are specified, with unresolved restrictions closed.
Evidence to attach: asset-rights schedule and migration acceptance step. If weak: ask for concrete delivery terms. Open-source definitions do not by themselves guarantee that a specific service will export your working system.