I have never been big on subtitles, but decided this book could use one, to convey that while the title and cover are similar to Columbine, Parkland has a very different focus. (Different time, different situation, different goal.)
I loved the simplicity of the cover, though, so I pitched an idea to my publisher: an inside subtitle, which will appear on the title page inside, and on book sites like Amazon and Barnes & Noble, but not on the cover. They loved it.
So it is now Parkland: Birth of a Movement.
And it's also available for pre-order, BTW. It's at all the major sites, and I've got direct links at my Parkland page.
Here's what it looks like on Amazon: