EPA is revising the format of 40 CFR part 52 for materials submitted by North Carolina that are incorporated by reference (IBR) into the Forsyth County portion of the North Carolina state implementation plan (SIP). The regulations affected by this update have been previously submitted by the Local agency through the State agency and approved by EPA. This update affects the SIP materials that are available for public inspection at the Office of the Federal Register (OFR), Office of Air and Radiation Docket and Information Center, and the Regional Office.