Boeing 767 Speedtape.
 

Can anyone throw any light on exactly how the speedtape works, and what is "driving" it? Why do we see differences between the speedtape information and the orange "bug" on the ASI? My company uses 230kts as the maximum speed until F5 has FULLY retracted to F1. Is this necessary? Any references would be welcome. Thanks. :ugh:

Orange bug = barber pole until clean
 

As a technique, many use the orange bug as a Vne until clean. When things are very busy (or a pilot new to the jet is flying), this technique will prevent flap overspeed better than the pitch bar...especially at high gross weights when min maneuvering speed is near max flap speed.