14.) Failure to re-identify the white conductor in cables installed for the purpose of switching, employing the white conductor as an ungrounded conductor.
200.7 Use of Insulation of a White or Gray Color or with Three Continuous White Stripes.
Section 200.7(A) requires that grounded conductors be identified by white, gray, or a conductor with three continuous white strips on a color other than green. Section 200.7(C), covering circuits of 50 volts or more, allows a cable assembly containing a conductor marked with white, gray or that has three continuous white stripes to be used as an ungrounded conductor to supply the switch in a single-pole, three-way, or four-way switch loop. This is allowed provided that the conductor has been permanently re-identified at all terminations and at each location where the conductor is visible and accessible indicating its use as an ungrounded conductor. Note that this conductor shall not be used as a return conductor from the switch to the switched outlet.
Where a cable assembly contains an insulated conductor for single-pole, 3-way or 4-way switch loops and the conductor with white or gray insulation or a marking of three continuous white stripes is used for the supply to the switch but not as a return conductor from the switch to the switched outlet. In these applications, the conductor with white or gray insulation or with three continuous white stripes shall be permanently re-identified to indicate its use by painting or other effective means at its terminations and at each location where the conductor is visible and accessible.