Utiliser "signal flag" dans une phrase

1. In 1961 the main types of communications were voice, signal flags, Morse code, and crypto, using UHF and VHF frequencies

2. On top of the fort a line of signal flags were hauled up a halyard

3. While waiting for the C-142A carrying her M20 armored command car to roll towards the tarmac area of the city’s central airfield, now bustling with activity, Ingrid started chatting with the very young woman on duty as the tarmac ground guide, who was wearing a fluorescent vest and was holding a pair of small red signal flags

4. It was always possible the other ship’s signal flags had been a bluff, an attempt to convince Rohsail it had friendly support close enough to read its messages