In my case i put an extra letter with the date of seperation, and then divorce since it was less than 2 years. I also included a copy of divorce certificate. Make sure to add your name at top of letter so they can reference to app.
In my case it was just a break up of a three year relationship. No divorce. I did mention that I was the one that initiated it, just to get the point across that I am not perturbed by the event lol