I apologize for the delay in responding to this, I was trying to get a definitive answer from those involved in the certification process. After checking around some, I've been told that if you follow Formats 2016 (and put that in your letter that goes with the manuscript), you would be fine. Braille Formats 2016 says to use
The End
enclosed in TN indicators (so initial cap, not full caps).
Cindi