Example: Section 86.411-78 applies to 1978 and subsequent model years until it is superseded. If a § 86.411-81 is promulgated it would take effect beginning with 1981; § 86.411-78 would apply to years 1978 through 1980.
Example: When considering 1979 vehicles a reference to § 86.411 implies § 86.411-79 . However if no § 86.411-79 has been promulgated then § 86.411-78 is implied; See paragraph (a) of this section.
40 C.F.R. §86.404-78