Page 87-88 2012-13 Wrestling case book and manual;
Section 7
#2 Illegal holds/maneuvers include, but are not limited to:
k. holds/manueuvers putting pressure in the throat and/or carotid artery;
q. front quarter nelson w/ the chin;
y. any hold/maneuver used for punishment;
z. any hold/maneuver with pressure exhorted over the opponent's mouth, nose, throat or next that restricts breathing or circulation;

6. The headlock with an arm encircled at or above the elbow is a legal but potentially dangerous hold/maneuver. Because of the dangers present when this hold/maneuvers used, referees are cautioned to be in a position to observe the hold/maneuver carefully. There are occasions when the arm, which is included, is impaired. It is possible for the arm to be inadvertently moved into a position where it restricts breathing or circulation and is hidden from the referee's view. The face of the defensives wrestler may be forced to tightly into the chest or side of the offensive wrestler and his breathing constricted. The head and shoulder of the defensive wrestler in a legal headlock may be forced together to the extent the shoulder becomes a pressure point on the jugular vein or carotid artery, thus presenting a very dangerous situation that may or may not be obvious to the referee. Finally, the strength of the wrestler applying the headlock may result in twisting, constricting or comp active damage to the neck and present serious problems. The very nature of the legal headlock prevents the defensive wrestler from indicating pain or distress when his opponent is of equal or superior strength. Because there may be no visible signs of distress until the problem becomes so serious the defensive wrestler may have lost consciousness, referees are cautioned to be very alert during this situation so they can prevent a potentially dangerous situation from becoming illegal.