„This was a three-thread cording machine fitted with a combination retard attachment. Only certain type L machines were fitted with this retard which affected the two thread cording process. Instead of the thread wrapping itself around the chain stitch with every revolution as was normal with the two-thread cording it could be made to wrap itself every other stitch or every third stitch or even every sixth stitch. This resulted in the second thread making a long slanting wrapped stitch over the chain stitch instead of the usual close twisted cord. When the retard was used with the three-thread cording, part of the soft wool, floss or similar thread was seen with the second thread slanted across it.“
(Quote from Machine Embroidery a complete guide by Christine Risley)