JD 830 3Cyl. 1974 what is the lever to the right and below the seat has letters

[RottenGround]

JD 830 3Cyl. 1974 what is the lever to the right and below the seat has letters for the position not sure has something to do with the hydraulics

 

[Zebrafive]

It's the implement control for your 3pt hitch. Labeled D LD & L.
D = Depth control.
L = Load control
LD= Combination Load & Depth control.

 

[RottenGround]

I know the depth would be for a plow not going to deep but what would the load control be for

 

[Zebrafive]

Load is to maintain a constant load on your tractor. If the load is increasing it will raise the implement, when the load decreases it will lower the implement. I am not talking raising completely out of the ground, just enough to maintain the load.