Command - Prb_DrawGrid
This tool will open the Draw Grid dialog.
To draw grids that are unequally spaced then you should enter in the Distance between grid lines field the distances separated by spaces or comma's. If you are working in inches units, then you can only use the comma to separate the distances because the space can be used to denote feet and inches.
When you click OK, the grid will be drawn at the origin.
By checking Change placement manually you will be prompted to select the insertion point and indicate the X and Y axes.
You can Move / Rotate / and Stretch the resulting grid lines. They are regular lines which have their grid name attached.
By convention, the grid line numbering system will begin at the bottom-left hand corner, incrementing along the X and Y axes.