Why dressage letters are in that order

8. After riding 500 20m circles in rapid succession, who can remember the alphabet?
7. The letters are consecutive and in alphabetical order, in a now extinct language spoken only by early 18th century Hanoverian carriage horses. 
6. The very first dressage arena was designed by the lowest-bid contractor. 
5. The letters were originally laid out by beleaguered riding pupils to facilitate pranks on their instructors, in which the pupils would pretend to be schooling various movements and figures while actually spelling out slanderous curses, in German, against their cruel and heartless instructors, their diabolical horses, and whatever silly person invented this dressage thing in the first place. 
4. The letters are actually advertising billboards paid for by Sesame Street (This piaffe-passage transition was brought to you by the letter G!). 
3. Well, the letters are supposed to be in alphabetical order, but somebody's Trakehner keeps getting out at night and rearranging them.
2. The other letters in the alphabet are there all right, they're just invisible--what do you think your horse has been spooking at all these years? 
1. What, you mean they're NOT in alphabetical order? Hey, that would explain why nobody else seems to understand how I've organized the office files...