Lindren's great run just missed the World Junior Record set by Bruce Kidd two years before in the same meet. The US talks about High School Records. The rest of the world talks about Junior records and and age records.
Bruce Kidd had completed his 13 years of grade and high school by age 18 and was attending the University Of Toronto at that age.
By the way, the distance coach at the University Of Toronto was Fred Foot. Our EYTC teammates, Bill Crothers, an Olympic Silver madalist at 800 in 1964, and David Bailey, Canada's first four minute miler also attended the University of Toronto and were members of the East York Track Club.