From Reversible Two Color Knitting by Jane Neighbors This stitch has a slide after the cast-on that I am interpreting to mean that row 1 is RS for this version, but nothing else changed.
CO in light, rows 1 & 2 in dark, row 3 in light, rows 4 & 5 in dark, row 6 in light
Shown with a cast-on count of 24 stitches.