A Note reviewing the principal SEC, NYSE, and Nasdaq rules and regulations governing the disclosure of material non-public information of a reporting company. This Note discusses issues such as the duty to disclose, how to determine what is material information, and the timing of disclosure. It also details how a company is to provide notification to the NYSE and Nasdaq when disclosing this type of information and the consequences of failing to provide notice. This Note does not address the specific requirements of Regulation FD. For a detailed analysis of Regulation FD, see Practice Note, Complying with Regulation FD (Fair Disclosure).