What is this red dot on the 50mm f1.4?

[vd853]

I have the 50mm f1.4 USM. What is this red dot on it? the dot is between the f22 indicator. I am thinking it means f1.4?

 

[white]

Looks like the infrared focusing indicator. That vertical line is the "normal" focusing indicator; since infrared is beyond what we can see, that dot is there so you can adjust your focus.