The International Signal For "Pull Over, You Are Slow"

Apparently, flashing your brights at the car in front of you to get them to change lanes IS an internationally recognized signal. At first, I only realized it was happening when riding with other westerners. Then I noticed the Chinese drivers that work with us doing it and I assumed that we had influenced them. Then when I saw the taxi drivers doing it (and taxi drivers being on the receiving end as well), I realized it was internationally known. However, it seems to only have about a 10% effectiveness rate in achieving the desired result, i.e. the guy driving 35 MPH in the passing lane of the 75MPH highway changing to the middle or right lane. One step at a time...