My take (and my take won't matter for long...
Treaties whether in private or public consist of what IS said rather than what isn't said.
There are SOME norms though, Nothing can be sent into your Provinces that can cause harm to the province nor Dominion as this is counted as an act of war.
Since most of the treaties I have seen are very specific and complicated, I have a couple of words for you...SIMPLIFY THEM.
Say Trumanator and I had a treaty negotiation and he played a stealth Nation.
It might go something like this: I (Arco) propose a 3 turn nap to begin on turn 11.
No stealth armies may pass thru my territories unless permission is granted and nothing other than regular scouts can enter each others territory.
He might reply with " I would like province #23,45,and 55 and you take #29,45,52 as our territorial line.
DONE.
We know: How Long, Boundaries, and Special considerations.
If we put it public we run the risk of other Nations knowing where we are..BUT we will have to hold to it.
If we don't put it public, we run the risk of it being broken when convienient by one of the parties and NO whining is allowed.
KNOW WHO YOU ARE DEALING WITH, and that only comes from expieriance.
Don't get caught up with what is not said...if in doubt ASK.
Trumanator is correct, ALL these negotiations should be done in privite as we don't need to know any more than you want us to.
We all form reputations, there are 4 or 5 in here that I would trust if they just said "you want a Nap 3" and I would know they would never break it and would not abuse it.
THATS a good feeling in these games.
My opinion of course