Roger that or usually simply Roger (nowadays also often spelled in lower case) is a phrase used in aviation and the military to confirm that a message has been received and understood. It was popularized by radio transmissions of NASA’s Apollo missions and by military fiction and is now sometimes used jokingly in everyday contexts. But how did it come into existence?
It all started with the big bang, then the dinosaurs… Fast forward a little bit, in the 1940s, the American military and British RAF used a spelling alphabet different from the current well-known Alfa, Bravo, Charlie. If you don’t know what a spelling alphabet is: It is a set of easily distinguishable names for the letters of the alphabet used in conditions where misunderstandings (such as mistaking “M” for “N”) could be fatal.
The letter “R” was used as an abbreviation for “received” back in the times when messages were sent via telegraphy (in Morse code), and the practice of confirming that a transmission was received by sending an “R” back was extended to spoken radio communication at the advent of two-way radio during World War II.
The phonetic alphabet used by the British and American military during the World War II was:
When a soldier or a radio operator said “Roger” after receiving a transmission, he was simply saying “R” for “received”. The alphabet has changed since then, but the practice of replying to a message by saying “Roger” stuck.
It is just a coincidence that two-way radio became widespread during the relatively short period when the phonetic name of the letter “R” was “Roger”. Before 1940, it used to be “Robert”, and from 1956 on, it has been Romeo. Had the technology arrived a little bit earlier or later, we might as well have been saying “Robert that” or “Romeo that”.