Effective January 1, 2017, both the 2016 FEI Seniors (Prix St. Georges thru Grand Prix Special) has 40 changes. The Juniors & Young Riders tests have 48 changes. Most of the changes are either "rebracketing" where the boundary between two movements is changed and/or an additional more defining element is added to a movement. The rebracketing is causing diagram changes. Watching the tests being ridden, the viewer would see no differences. However, because of the rebracketing and changes to the directive ideas, the scoring has definite changes. Judges will need new books to ensure their diagrams match the score sheets and new books are advisable for riders.
Dressage Illustrated plans to have new 2017 Dressage Illustrated diagram books for riders and judges available by December 15, 2016 or later if the final FEI approval is delayed.