We study the value of commitment in verifiable disclosure games when the receiver faces non-quantifiable uncertainty about the evidence environment. The sender has stochastic access to hard evidence and may disclose or suppress it; the receiver chooses a decision rule to maximize her payoff guarantee. When ambiguity concerns the payoff state, the receiver has strict incentives to soften her standards ex post after non-disclosure, making commitment strictly valuable. When ambiguity concerns the sender’s expertise, incentives reverse: the receiver prefers a stricter reaction than is ex-ante optimal, so prespecified, hard-wired rules for non-disclosure improve payoffs for both sides.