This relaxation protocol was developed by the wonderful trainer Suzanne Clothier. You can purchase the DVD, streaming video, or course to get full information straight from the source. The story of Jinx the Belgian Tervuren written here is a wonderful example of the power of this training technique.
The RRR teaches the dog to relax while lying down, with the owner also relaxing next to them as a cue to the dog. At first it’s very short, and builds duration over time. Because it emphasizes offered rather than cued behavior, the dog is able to learn to self-regulate, even while watching the world go by around them.
Written instructions for the protocol are here (PDF).
Video examples, from start to finish
Relaxation Protocol: Suzanne Clothier - Indoors by J-R Companion Dog Training takes you through all the steps as written above
Using Suzanne Clothier's Really Real Relaxation Protocol by Kizz Robinson shows a dog learning the RRR in real time:
Prevent Demand Behaviors With This Relaxation Protocol by Noble Woof Dog Training shows a dog practicing in a calm location outdoors:
Really Real Relaxation with Kona and Kit by CanineCountryAcademy shows two dogs in the same room learning to relax with their own handlers:
And my favorite video - Really Real Relaxation Protocol—advanced by Tegan Moore shows a dog switching between active work and focus with his handler, and relaxing together: