More or less the dwarfs follow the same convention as high stand signals. Read the lights as if they were a two headed high stand signal. Disregard the lower red lights when reading them like you would if they were high stands.<br /><br />There is a flaw in the logic however because you would not expect the two signals below to be &#039;Slow&#039; but they are.<br /><br />G/R dwarf would be read as G (and a green dwarf is Slow Clear)<br />Y/R dwarf would be read as Y (and a yellow dwarf is a Slow Approach)<br /><br />The Y/Y (Medium Advance Approach) dwarf doesn&#039;t follow any obvious convention.