[7.3.4]
Total reflection of a light ray at the boundary between two media occurring when the angle of incidence in medium 2 exceeds the angle whose sine equals n1/n2, the ratio of indices of refraction when the ray is propagating in the direction from medium 2 toward medium 1.
NOTE: This term was changed in RP-16-17 Addendum 4.
Previous name: total internal reflectance, TIR