Ok so I am a little confused does the underlined part override the first part in bold or do both parts apply? The way I read this is, if a car came with 16" wheels and is classified in ITR you can run 15" wheels. Is that correct or do both apply?

7. Wheels/Tires
a. Any wheel/tire may be used within the following limitations:
1. Cars originally equipped with twelve (12) inch wheels may
fit thirteen (13) inch wheels. Cars originally equipped with
metric 365 wheels may fit fourteen (14) inch wheels, and
cars originally equipped with metric 390 wheels may fit
fifteen (15) inch wheels. The above-mentioned cars as
well as those cars originally equipped with thirteen (13)
inch or fourteen (14) inch wheels may fit up to a fifteen
(15) inch wheel. Cars may not fit wheel diameters smaller
than those listed on their spec line. All other cars shall
retain the wheel diameter fitted as original equipment for
their make, model, and type. Knockoff/quickchange type
wheels are prohibited. Wheels must be made of metal.
Cars classified in ITR may utilize any wheel diameter up to
17” or retain their stock diameter wheels if larger.