This paper reviews the literature on Securities and Exchange Commission (SEC) Comment Letters. The economic significance of Comment Letters may be relevant to public policy considerations and the evaluation of related research. La Porta et al. [(2006). What works in securities laws? The Journal of Finance, 61(1), 1–32] cast doubt on the value of public regulation enforcement. SEC review limitations and the institutional setting likely limit the impact of 10-K/10-Q Comment Letters. Severe resolutions are infrequent, and market impact evidence is limited. Recurring filing reviews may deter substandard reporting, and IPO Comment Letters offer a powerful setting, but neither has received much research attention. Empirical challenges are also examined.