What does FN+C does on the Blackwidow mini hyperspeed?

Hello all,

I finally puled the trigger and got myself a Hyperspeed, despite its steep price and the fact that it doesn't come with a tactile switch option... first day using it, and I am getting to like it. One of the features I like a lot, is that when pressing the FN key (next to right alt), all keys with a secondary function light up white (a feature not present into Ducky keyboards).

Onto my keyboard, pressing FN also makes key C to light up, however there is no inscription to the front of the key what secondary function is when pressing fn+c.

Does anyone have an idea?

Thank you.
Christos