So, what is the correct way to install a fence?
1. On the line
2. Just inside the line on your side

For clarity, property has been surveyed and markers put on line, not my fence but land sold behind my property

On the line. If you have to go around obstacle with fence, I’d come to the inside of the line myself. Then I’d know for certain, anything inside the fence is on me. Friend or foe.

I always install just inside my property line unless you are splitting cost with your neighbor. That way you can build what you want and if your neighbor doesn't like it they can put what they want up on their side.

I will also add that the "neighborly" thing to do is put the pretty or best side, if there is one, facing toward your neighbor.

Probably barbed wire for cattle

4-6 inside your line. Then when the round-up mist kills a good clean edge he can’t say anything.

If ita a farm fence and both sides are used, we always went on the line. One party bought materials and the other provided the labor. I am sure that's not a thing in most areas now, but I'd still put it on the line.

I have nothing to do with the fence, new owners fence. We have horses our fence is inside the line it also is not adjacent to this new fence. That’s why I was asking about the line issue

Fencing,signs and fire breaks on the line for me.