Ok, I just browsed through that link and the following section caught my eye:

1.3.020 For massed start road and cyclocross events, the frame of the bicycle shall be of a traditional
pattern, i.e. built around a main triangle. It shall be constructed of straight or tapered tubular elements (which
can be round, oval, flattened, teardrop shaped or otherwise in cross-section); the centerline of each element
shall always be straight. The elements of the frame shall be laid out such that joining points shall follow the
following pattern: the top tube (1) connects the top of the head tube (2) to the top of the seat tube........

The following 2 sections jump out at me:

"The elements of the frame shall be laid out such that joining points shall follow the
following pattern: the top tube (1) connects the top of the head tube (2) to the top of the seat tube..."

So compact frame geometries should be illegal for mass start races?

"It shall be constructed of straight or tapered tubular elements .....the centerline of each element
shall always be straight."

Wouldn't that mean that bikes with curved stays are illegal?