World Athletics wrote:
From 30 April 2020, any shoe must have been available for purchase by any athlete on the open retail market (online or in store) for a period of four months before it can be used in competition.
The sole must be no thicker than 40mm.
The shoe must not contain more than one rigid embedded plate or blade (of any material) that runs either the full length or only part of the length of the shoe. The plate may be in more than one part but those parts must be located sequentially in one plane (not stacked or in parallel) and must not overlap.
For a shoe with spikes, an additional plate (to the plate mentioned above) or other mechanism is permitted, but only for the purpose of attaching the spikes to the sole, and the sole must be no thicker than 30mm.
Basically they gave everyone a pass on prototypes through the spring marathon season so non-Nike company's can try to catch up. But they clearly don't' want the integrity of the Olympic marathon to be jeopardized like it was in 2016.
The problem is the non-Nike athletes may be screwed for the Olympics unless these companies can release their vaporfly copies by March which is 4 months before the Olympics. Saucony's shoe is supposed to come in June. Jared Ward may be screwed.
It seems to me that they should consider some sort of waiver of the rule through the Olympics. The problem isn't protypes. It's prototypes that were way better than what anyone else has.
Officially rule amendment.https://www.worldathletics.org/download/download?filename=1a53ca10-7f30-46e4-83fe-e7ff5fda2c60.pdf&urlslug=C2.1%20-%20Technical%20Rules%20(amended%20on%2031%20January%202020)