When I took my Technician test some 20 years or so ago, we had to memorize the phonetic alphabet, which I think is the same one used in the military. I was taught that it was international, similar to morse code. It used words such as "Mike" for the letter "M" and "Juliet" for the letter "J" and "Zulu" for the letter "Z".
On VHF, I hear these used almost exclusively, but I recently passed my General class exam and started getting on HF and listening to both local and DX stations use words like "Mary" for "M" and "Japan" for "J" and "Zed" for "Z".
Is there really a standard or do people just make up their own? It has caused me quite a bit of confusion since I hear stations use words like "Japan" and I am not sure if they are using phonetics or whether they are actually in Japan.