From the NRA rule book, modified for static targets at 100 yards.

(A) SLOW FIRE - When ready to start a match, the Chief Range Officer commands, "RELAY (number), MATCH (number)," or naming the match, "TAKE YOUR POSITION ON THE FIRING LINE. DO NOT HANDLE YOUR RIFLES. (Rule 10.1.1) 

(1) YOUR PREPARATION PERIOD WILL START IN TWO MINUTES." Competitors take their places at their firing points. After the two minute period then the command is given, "YOUR THREE MINUTE PREPARATION PERIOD WILL BEGIN NOW." Range Officers check competitors as to correct relay, firing point number. At the end of three minutes the command is given "THE PREPARATION PERIOD HAS ENDED. THIS STRING OF FIRE... WILL BE TWO SIGHTERS AND (number) SHOTS FOR RECORD IN A TIME LIMIT OF (number) MINUTES. WITH ONE ROUND LOAD...IS THE FIRING LINE READY?... THE FIRING LINE IS (IS NOT) READY." If not ready and when the firing line is ready, "RESUMING COMMANDS, THE FIRING LINE IS READY. YOUR TIME WILL BEGIN AND YOU MAY FIRE WHEN READY.

(2) "IS THE FIRING LINE CLEAR?" Range Officers assure that all firearms are cleared, actions opened and open bolt indicators are properly in place. If no one has replied "NOT CLEAR!" and Range Officers signal that the firing line is clear then, "THE FIRING LINE IS CLEAR. RELAY (just finished) REMOVE ALL OF YOUR EQUIPMENT FROM THE FIRING POINT." If, on the other hand, firing continues until the end of the period; the targets are withdrawn at the end of allowed time. "CEASE FIRE. TIME HAS EXPIRED. HAS ADDITIONAL TIME BEEN AUTHORIZED... ON THE RIGHT... ON THE LEFT?" If additional time was authorized then, "THOSE TARGETS AUTHORIZED ADDITIONAL TIME, YOUR TIME BEGINS WHEN YOUR TARGETS APPEAR." The targets are run up for additional time. "ALL OTHER COMPETITORS CLEAR YOUR RIFLES AND INSERT OPEN BOLT INDICATORS.

At the end of additional time or if signaled by Range Officers that firing is complete, "CEASE FIRE. CLEAR ALL RIFLES AND INSERT OPEN BOLT INDICATORS." The line clearing procedure listed above (2) is used together with the removal of equipment procedure in (2) above and, if desired, the police brass and trash call procedure in (2) above. If additional relays are firing, the command is given, "RELAY (next) YOU MAY TAKE YOUR POSITION ON THE FIRING POINT WHEN IT IS VACANT BUT DO NOT HANDLE YOUR RIFLE.

Note: The tempo used to deliver these commands will establish the flow of your match. The best Range Officers (tower talkers) monitor the competitors as they are responding to commands. Then they adjust their tempo of the commands to keep the match moving crisply without causing undue stress on the competitors. Common sense, compassion, a keen sense of pace and a good knowledge of this rule book are characteristics displayed by talented Range Officers (tower talkers).