Every capital letter after the first doesn't register.

For example if you type, "Hello How Are You" it will show as "Hello how are you".

"Enable message formatting [Will control caps, message format] (true - yes/false - no)": true,

Edit:
If you have this set to true you can only have one capital letter in the sentence.
Or maybe the whole message. I'm not sure which at the moment.
It's probably best to just disable this as it tends to piss off players.
At least in my experience.