Last Friday night, with 0:20 remaining the second period, and clock running, Team A commits a false start. As my U is stepping off the distance penalty, I realize that we may also have a 10-second subtraction from the game clock. My H talks to Team B (ahead in score), and they do, in fact, wish to impose the 10-second subtraction. At the same time, my L is talking to the Team A head coach, reminding him that he can avoid the 10SS if he takes a charged team time out, which he elects. So, I signal T/O for A.
Following the T/O by A, the next down is played, with the ball (in Team A's possession) being declared dead in the field of play, short of the line-to-gain. Team B committed a facemask foul during the down, so the game clock is stopped with 0:12 in the period. After penalizing, instead of winding the game clock on my whistle, 3-4-3 is invoked, and the game clock starts on the snap.
So, still haven't had an actual 10-second subtraction from the game clock. I have invoked 3-4-3 in the past, but not very often.
Like I said, nothing new or difficult, but things that don't happen very often. We were on our toes and got both, with better-than-average efficiency.
Those things make it fun.