Sorry if this is a noob question.
I have two 5 Deutsche mark coins from 1975 and as far as I can tell they are exactly the same (has some sort of bird of prey on front) except that that under the 1975 one has a F while the other has a J. I have a few more European coins with a single letter on their front.
Are these letters the city that the coin was minted? I'm assuming this because I have two WW2 Australian coins with a S and a D respectively, which means that they were minted in San francisco and Denver (don't ask e why this is the case).