If menu selections are made by keyed codes, each code should be the initial letter or letters of the displayed option label, rather than assigning arbitrary letter or number codes.
Additional Information:
Meaningful (as opposed to arbitrary) codes will facilitate learning and reduce errors. For example, m = Male, f = Female is preferable to 1 = Male, 2 = Female. Options might be numbered when a logical order or sequence is implied. When menu selection is from a long list, the line numbers in the list might be an acceptable alternative to letter codes.