This signal is used by the Referee to indicate holding has occurred.
PenaltyThis is a 10 yard penalty and is most often called against the offense, when it will be assessed from the basic spot.
It may also be called against the defense on a forward pass play when a defender holds an eligible receiver - this attracts both a 10 yard penalty and an automatic First Down.
Begin the motion with one arm held in front of your chest and bring the other hand up and grasp the other forearm and pull it down slightly in an unhurried manner.
Finally point to the offending team by stretching an arm out from the shoulder to the horizontal.