Three way light switch with power feed via the light

In this light switch wiring diagram the power feed joins the circuit via the light fixture where a two wire cable (C2) runs from the light, to the first 3-way switch (SW1), and a 3 wire cable (C3) joins the two switches. The hot source is spliced to the white wire (which should be marked as being hot with black tap) and run through to the common terminal of SW1, and from here the hot from the light is spliced through to the common terminal of the second 3-way switch (SW2).

3 way switch with power feed via the light (single light)