Codebooks have been integral to Morse code communication since its invention in the 1830s. Commercial telegraph companies developed extensive codebooks to reduce transmission costs by substituting long phrases with short codes. During wartime, military codebooks were highly classified documents, with nations constantly developing new codes and attempting to break enemy ciphers. The famous Zimmermann Telegram of 1917, decoded using diplomatic codebooks, changed the course of World War I. Today, while technology has evolved, the concept of personal codebooks lives on in our digital tool, preserving this rich tradition for a new generation.