The Dinosaur attraction at Animal Kingdom is one of the more "thrilling" rides at this park, and my son and I ride it often. However, I noticed this detail for the first time today. There is writing on the right hand wall, near the beginning of the ride, with an interesting hidden tribute. The sector numbers and letters have meaning. CTX refers to the original name of the attraction, Countdown to Extinction. The WDI is Walt Disney Imagineering. Finally, the AK98 refers to Animal Kingdom and the year that it opened......1998.