Any large concentration of power is likely to cause an EMI spur. While the Section 3.3 section discusses this with trace width, high power concentrations can be found in other areas in the PCB. Vias and passive components tend to have these higher concentrations at connection points. If the via is significantly smaller than the trace width, for example, this transition can act as an antenna. Similarly, a large passive component pad connecting to a smaller trace width or a transition between two planes can have the same effect.