Yes, G stands for general low alloy steel electrodes. The chemical composition of the electrode contains at least one of the elements stated in Table 2 of SFA 5.5 for either Mn, Si, Cr, Ni, Mo, and V, and Cu. You can have various stregnth levels (from 70 Ksi up to 120 Ksi)depending on the supplied chemical composition. For your electrode, you have 70 Ksi tensile stregnth. Review AWS SFA 5.5.