Use BEFORE running a confirmatory analysis, an experiment readout, an A/B test, a policy evaluation, or any study whose credibility depends on not having fished for the result — especially causal/econometric work. Locks the hypotheses, estimand, primary specification, sample and exclusions, and the robustness suite while the outcomes are still unseen, so the analysis is confirmatory rather than a specification search. Use whenever the user says "evaluate whether X worked", "test this hypothesis", "did the experiment move the metric" (outcomes still unseen — already-unblinded results route to causal-identification and analysis-review), "register this analysis", or is about…
