The French text includes the "one of" phrase which is the way the English text also read until the latest change in 2012 to add the ECE standard. It seems clear that the English version has not been proof-read for consistency with the French version or checked for clarity of intent. Adding "one of the following standards..." to the English version makes it consistent with the French text and also makes it conform to the wording, and intent, of the previous versions which date back over 40 years. As I recall, the original intent was to require the CSA (Canadian standard) as the only permitted standard until it was realized that the CSA was not an approved standard anywhere in the USA (where, at the time, most states required a DOT helmet) and riders touring Canada and the USA would be required to carry two different helmets. It was also finally realized by the Ont. Dept. of Transportation that the helmets generally in use by riders at the time they began to make helmets mandatory were designed and certified to USA (USDOT, SHCA Z-90, Snell) or British (BSI 1869 or BSI 2001/56) standards. Hence the number of standards written into the regulation back then.
It was also found, at the time, that the OPP motorcycle patrol officers - the "Golden Helmets" - were wearing helmets which were not approved by any standard, nor, as designed, were capable of meeting any of the standards mentioned above. All this was discussed in detail in public hearings by a Select Committee of the Ontario Legislature on Traffic Safety back in or around 1976, at which several Canadian Vintage Motorcycle Group members appeared in order to put forward their views on improving motorcycle safety with reasonable, sensible legislation.
AFJ