A for 'orses
B for mutton
C for 'th highlanders
D for 'ential
E for brick

Since this thread seems to have gone down the tubes (I think it was my last comment that killed it) I will put this here:

IIRC it was tippyc who wrote something like "Unless I have missed something the previous guy [i.e. me] is crazy".
Although the two alternatives are not mutually exclusive each other (and I tend to share Yossarian's view of being thought crazy), yes, you have missed something, though I can understand your confusion.
My serious point was that when spelling out a word or reciting a spelling alphabet, you can say "A for . . ., B for . . ." etc.). As an illustration, I quoted from the Cockney alphabet, which -- though humorous -- does illustrate the point, and in fact requires the use of the preposition "for" (particularly for the letter 'C').
(:-)