From the just-released "New Annex XIII" to the FEI "Dressage Stewards Manual":
"The steward may also ask the rider to walk for a certain period in situations where the rider’s stress may cause undesired riding."
I assume that means asking the rider to walk the horse under saddle, but it would be better if the steward made the rider dismount and go for a walk to clear his or her head and think about how much they'd enjoy being chased around with their nose pinned to their chest.
Seriously, though guidelines in response to the use of rollkur/hyperflexion are welcome, it's hard to believe that these are anything more than CYA measures. The FEI may just as well remind the riders that they should assume that they are being videotaped at all times.