Well it is just basic ee stuff, ohm's law. There are such components as zero ohm resistors, which of course really are not zero as that would imply superconductivity However, they are just smd-resistor shaped pieces of wire wich usually take place as jumper components. Joerg is making a joke on the specs of the component, if it really was zero ohm you could not give a power rating to it, neither specify a tolerance. Quite funny really