| 1 | Making identification signals with flags. | |
| 2 | SEMMNS A system-wide limit on the number of semaphores in all semaphore sets. | |
| 3 | These limitations also lessened the effectiveness of the semaphore, a modern precursor to the electric telegraph. | |
| 4 | SEMMNI A system-wide limit on the maximum number of semaphore identifiers . | |
| 5 | The signalman on the ship wigwagged the good news to the other ship. |