These settings are used when you don't explicitly state which nodes should be saved in a simulation. Useful settings are "Save Device Currents", "Save Subcircuit Node Voltages", and "Save Subcircuit Device Currents". Device voltages and internal device voltages are only of internal program development use.
Save Device Currents: Check this so that you can plot device and terminal currents. You will also need it to be able to plot dissipation.
Save Subcircuit Node Voltages: You will need to check this to plot voltages in hierarchical designs.
Save Subcircuit Device Currents: You will need to check this to plot currents in hierarchical designs.
Don't save Ib(), Ie(), Is(), Ig(): This saves only the collector(drain) currents of transistors in the interest of reducing the size of the output .data file. This is useful for IC design, but it using it means that there isn't enough data available to compute transistor dissipation.
Save Device Currents: Check this so that you can plot device and terminal currents. You will also need it to be able to plot dissipation.