Originating in Great Britan, the "V-sign" is very basically the equivalant of the finger (middle finger). This is all you will care about knowing.

"How you do dat?", you may ask. Simply follow these steps, and you will learn.

Step 1: Get in the air by almost any means, exeptions being actions such as a spring-vault.
optional - enter reaction time (R) to go into slow-motion

Step 2: Do a 90/180 Turn (Q)!

Step 3: Mele(MOUSE 1) as you fall!

These combined actions should cause Faith to (briefly) display her well-hidden traits of the British and her hate with her right arm in the lower portion of the screen, as shown in the low-res image that heads this guide.

Here are some things to consider...

• Several people are getting confused. This is not the "Peace Sign" or "Victory Sign". In those two, the back of the hand is to face the gesturer. However, for the sign described in this guide, (notice that) the palm of the hand faces the gesturer. In addition, the offensive sign is often used along with an upward motion.
  
• You must do these actions rapidly, espescially if you are on flat ground.
  
• Depending on your abilities, you should be able to mele multiple times before you, well, can no longer do so, while falling.
  
• You (should know that you) can't use Reaction Time in time trials.

I am glad to say that I've found the action combonation myself (I had been ragin' anda button smashin') , while my knowledge of the possibility of this pressumed secret goes to some youtuber that must've removed the video or something. For the life of me, I cannot find it. And, no, it's not that
one video that has the guy with the XBOX 360 controller and shows you the combo. "Well, if you saw dat then you'd know dat combo!" you may say. Well maybe I just saw that video just now while trying to find the other one, which by the way did not show the combo. I swear that I indeed found the combo myself. Ms. Jackson may object to that, but, sorry, I am fo reeeeeeaall.