Mod suffix letters

Toe_Jameron

I hadn't seen this in mod guides, but players posting characters seem to have mark 5 A mods. Is "A" the best to get?

Thanks in advance!
-Toe

Darth_cowboy

Unfortunately all 5 dot mods leveled up all the way are A, what's important is what does it start at that suffix just determines what color the mod currently is

Toe_Jameron

Ok. I see now. I finally got an 'A' to drop. Looks like A shows all secondary boosts right away.
Thanks for the response!