Several people have pointed out that for college hockey the red line was
not used for two line pass going back at least 40 years and that its use
for icing was only added about 1980. I doubt the red line for two line
passes was ever used in college hockey because my recollection is that it
was added to NHL hockey during World War 2 to slow the game down because
the league was populated by a mix of very young and very old players.
--Steve