A.15.10:4.1 - Decide what could be lost
Ask what would make a return go wrong: losing the purpose, a condition of the method, an unfinished reasoning step, the location of a result, an access route or the occasion for returning.
Use what already holds that contribution. An open calculation, a marked physical arrangement, a working document or a shared task may be enough. Retaining another copy adds a consistency problem unless it serves a different use.
Choose a small preparation when reconstructing the contribution is likely to be difficult, costly or consequential. If it is cheap to reconstruct, leave it to the return. If the interruption is sudden, start with recovery in §4.3. This judgement needs no new estimate, form or justification record merely to make an ordinary reversible choice.