(C) Circuits of 50 Volts or More. The use of insulation
that is white or gray or that has three continuous white or
gray stripes for other than a grounded conductor for circuits
of 50 volts or more shall be permitted only as in (1) and (2).
(1) If part of a cable assembly that has the insulation permanently
reidentified to indicate its use as an ungrounded
conductor by marking tape, painting, or other
effective means at its termination and at each location
where the conductor is visible and accessible. Identification
shall encircle the insulation and shall be a color
other than white, gray, or green. If used for single-pole,
3-way or 4-way switch loops, the reidentified conductor
with white or gray insulation or three continuous
white or gray stripes shall be used only for the supply
to the switch, but not as a return conductor from the
switch to the outlet.
