Under that, there are sections such as Axis, X and Y axes, Time axes, Labels, ...
It sounds like what you need is the PPL TICS command. This lets you set the size of tic marks, and you can set that size to 0 so they will go away.
If you want to also remove the labels that go along with the tics, then you would want PPL AXATIC which controls the number of tic-marks and labels along the axes.