A signal displaying an aspect less restrictive than the danger aspect is termed as being taken OFF.A main signal displaying a yellow, double yellow or green aspect is known as being taken OFF.
II) Subsidiary signals
Subsidiary Signals are also of two types:
A) Shunt Signals
The most common position-light signals used for shunting show two white or yellow lights arranged horizontally for the on position, and two lights at an angle (the one to the left being higher) for the off position.