Window track adjustment. Use it if your window rattles, otherwise, no need to touch.
Not sure if it affects rattles any, but it is the tilt adjustment that affects how tightly the window seals against the top weather stripping. This sometimes need adjusting when you change from a hardtop to the soft top. They aren't always exactly the same. There are a few other adjustments you may need to be aware of for the windows.
Inside the door there is an upstop adjustment that determines how far up the window will go.
With the window down all the way, looking down from the top between the rubber seals that the window slides in, there are screws that hold the upper part of the window guides in place. These aren't adjustments, but often will loosen and prevent the window from going up all the way (like 3/4" short). Just reach in through that opening and tighten it. You can see it with a flashlight.