I have quesiton about the following rear suspension rule that is listed in the STU section of the STCS.

9.1.4.A.F.1 (page 473)
Cars that come with a solid rear axle or trailing arm suspension are
permitted an aftermarket or fabricated rear suspension. Cars with
an altered rear suspension must add 50 lbs. Cars with live axle rear
wheel drive may reduce the minimum weight by 50 lbs

What constitues an aftermarket or fabricated rear suspension? What may be fabricated? Can the OE design of the solid axle rear suspension be altered as a result of this allowance? IE: OE 4 link replaced by a fabricated 3 link.

Final question - is this rule additive to the two rules that follow it - 9.1.4.A.F.2 and 9.1.4.A.F.3.? Meaning that a solid axle car may have a "fabricated rear suspension" AND it must conform to 9.1.4.A.F.2 and 9.1.4.A.F.3.