The Office of Surface Mining Reclamation and Enforcement (OSMRE) is proposing to clarify its regulations pertaining to "Ten-Day Notices” (TDNs), which are set forth at 30 CFR 842.11 and 843.12. This rulemaking will clarify and provide guidance for the issuance of TDNs to State and Tribal regulatory authorities (RAs), the evaluation of RAs responses to TDNs by OSMRE, and informal reviews by OSMRE. This rulemaking is intended to remove regulatory uncertainty by defining terms related to TDNs that have been historically labeled ambiguous by the regulated community and RAs. These clarifications and explanations to the processes associated with TDNs will allow greater deference and flexibility to RAs as they investigate, respond to OSMRE inquiries about, and enforce potential violations that exist at coal mine sites.