is used to signal

6 triples
GPTKB property

Random triples
Subject Object
gptkb:Emergency_Position_Indicating_Radio_Beacons distress at sea
gptkb:The_Jolly_Roger a pirate's intent
gptkb:Flag_of_the_Red_Cross emergency medical services
gptkb:The_Last_Post the end of a duty shift
gptkb:The_Last_Post the end of the day
gptkb:The_Bourdon_Bell gptkb:time