My father's call up papers landed on the doormat from the army when he was 18 years old in 1952 and he fully expected to serve his country and fight in the Korean war. If he had been caught lying to try and get out of it the penalty was a £30 fine or 3 months in prison or both and if he had ignored his call up that also may have resulted in a prison sentence. My father went for his medical by army doctors and explained that he had suffered serious ear injuries in both ears during WW2, was suffering from what today is called PTSD due to his experiences in WW2 and was also suffering from recurring nightmares. After examining my father the army doctors graded my father as unfit for any military service due to the injuries he had received in WW2 but they said that he would have to repeat the process 6 months later. The result of the 2nd medical was the same as the first.
After my father's passing I found his call up papers that had been saved from 1952. I assume that there was also a form that had to be filled in and was handed in when he went for his medical.