The Scout sign is made with the right arm held straight out from the shoulder in a horizontal position, the elbow bent 90 degrees, with the hand in an upraised vertical position, the three middle fingers relatively straight (not spread wide apart), with the thumb holding down the pinky.
In his book, Scouting for Boys, Robert Baden-Powell chose the three-finger salute for Scouts to represent the three aspects of the Scout Promise:
Honor God and Country
Help Others
Obey the Scout Law
When you see another Scout holding the Scout Sign up, make the sign and remain silent.
The Scout salute shows respect. Use it to salute the flag of the United States of America. You may also salute a Scout leader or another Scout.
Give the Scout salute by forming the Scout sign with your right hand and then bringing that hand upward until your forefinger touches the brim of your hat or the arch of your right eyebrow. The palm of your hand should not show.
The Scout handshake is made with the hand nearest the heart and is offered as a token of friendship. Extend your left hand to another Scout and firmly grasp his left hand. Only use this handshake when both people are in uniform.