"cracks, holes, shell rot and decay, knots, depth of setting, soil conditions, and burn marks"
"Hammer test. Rap the pole sharply with a hammer weighing about 1.4 kg (3 pounds), starting near the ground line and continuing upwards circumferentially around the pole to a height of approximately 1.8 meters (6 feet). The hammer will produce a clear sound and rebound sharply when striking sound wood. Decay pockets will be indicated by a dull sound or a less pronounced hammer rebound."
"Rocking test. Apply a horizontal force to the pole and attempt to rock it back and forth in a direction perpendicular to the line."