The crosstalk is often limited in its use to circuits/conductors in close proximity, where the coupling path may be characterized by the mutual capacitance and mutual inductance of the circuits. Crosstalk should be a prime suspect in an Electromagnetic Interference investigation, or a candidate for examination in a prediction, if high transient current or fast rise-time voltages are present on conductors in close proximity to signal-carrying conductors. Electromagnetic coupling includes the coupling of an electric, magnetic, or electromagnetic field from one conductor into another, which is not necessarily in close proximity. When considering crosstalk between printed circuit board (PCB) tracks, conductors in a cable, or wires and cables in close proximity, it is important to determine if it is predominantly electric field or magnetic field coupling. Many of the computer-aided design PCB layout programs do allow crosstalk, and these include the "In cases" and "Applied Simulation Technology" programs.