Well, what it actually says is: "All drivers shall wear a full-face helmet with face shield bearing a Snell Foundation tag reading Snell SA2010 (FIA 8860-2009) or Snell SA 2015 (FIA 8860-2015)." The failure to include SA2020's would certainly appear to be an oversight, but it says what it says. I sent a text to Kiwi Steve about it, and assume the problem will be addressed somehow.
Jeff in Boise