General Order 64-A
Section II
Definitions Of Terms Used In This Order
20.8 Cross Arm means a horizontal support of wood or metal attached to poles or structures and which is generally at right angles to the conductors supported thereon.
A. Combination Arm means a cross arm supporting conductors of 0-750 volts and voltages in excess of 750.
B. Related Buck Arm or Reverse arm means a cross arm used to change the direction of all or part of the conductors on the line arm immediately above or below and which is generally placed at right angles to the line arm.
C. Clearance Arm means a cross arm supporting conductors installed on a pole of another line for the purpose of maintaining the prescribed clearances of this order which, if the other line did not exist, could be maintained without additional facilities. Where the shorter span length exceeds 125 feet, the arm so installed is considered a line cross arm.