(a) Except as otherwise provided in §§ 97.301 through 97.304 , §§ 97.306 through 97.308 , and subparts BBBB and CCCC and subparts FFFF through HHHH of this part, a CAIR NOX Ozone Season opt-in unit shall be treated as a CAIR NOX Ozone Season unit for purposes of applying such sections and subparts of this part.(b) Solely for purposes of applying, as provided in this subpart, the requirements of subpart HHHH of this part to a unit for which a CAIR opt-in permit application is submitted and not withdrawn and a CAIR opt-in permit is not yet issued or denied under this subpart, such unit shall be treated as a CAIR NOX Ozone Season unit before issuance of a CAIR opt-in permit for such unit.