Oh, and there is a little trick you need to look out for:
If you have a held chord as the last sound in your song, then the next chord with the period (which means, rest all instruments) must be a different chord. It can be any chord except the exact last held chord. [Most times, I just put C. since I write jazz and it's almost impossible a CMajor chord with no extensions would be my last played chord.]
I think I'm a little smarter after reading this. Thanks Matt. I've had frustrations getting proper held chord behavior at end of songs. I'm going to try and remember this next time.