ELI5: Explain Like I'm 5

International Code of Signals

The International Code of Signals is like a big book with pictures that helps people who speak different languages communicate with each other when they’re out at sea.

Just like we use words to talk to each other, ships use different flags and symbols to talk to each other. Each flag and symbol stands for a different letter, number or message. So, if a ship wants to say something like “Hello!” they would hoist up the flags for the letters “H,” “E,” “L,” “O” in that order.

Many different countries and languages use the same code of signals, so no matter where they’re from, everyone can understand what the other person is trying to say. It’s like a secret language that only sailors and captains know how to use!