Yes, it's right in the first paragraph of the Beyond 5/3/1 book under Big Lifts:
"The first part of the Boring But Big Challenge is that you will continue to perform the squat, bench, press and deadlift with the 5/3/1 sets and reps. You will increase the normal five pounds on the upper-body lifts and 10 pounds on the lower-body lifts after each cycle; nothing changes with regards to the progression. Make sure you begin this challenge with your training max set at 90% of your actual max. If you have to reassess your training max, then do so. The one thing that you will change is that you will NOT go for any extra reps on the last set. You will only do the required reps and move on."