It won't apply to your own horse because you can't ride your own horse at school. You can haul them in and ride in open arena times, but not in lessons, competitions, classes, etc because of IHSA rules.
They probably do have it on the dressage team, but the dressage team does not have a webpage like the hunt seat and western teams so I was not able to acquire the information
I 100% agree with you MIEventer. Becky Holder, while she was a great rider before, is a really great rider now! She's still not a stick, and I respect her for that but she slimmed down for the health of her horse and to be a better rider.