PROGMEM example

#include <avr/pgmspace.h>

const char message[] PROGMEM = "Hello, World!";  // Store string in FLASH

void setup() {
    Serial.begin(9600);

    // Read and print the message from FLASH
    char buffer[20];
    strcpy_P(buffer, (PGM_P)message);
    Serial.println(buffer);
}

void loop() {
    // Your loop code
}