A: I have copied a section from one of my spinning instruction booklets, Quick Novelty Yarns, here on line. Some recent books and articles use the two names indiscriminately but I prefer to use the term crepe yarn as one that describes an overspun yarn to be used in a collapse, crepe style fabric. Here is a scan of a cabled yarn so that you can see the distinct braided look.
A cabled yarn is usually a 4-ply yarn with a distinctive interlocking, braided look. It is made by plying a yarn twice. The first plying is in the normal direction, S if the singles were spun Z, but is tightly over plied. The second plying -- the cabling, reverses the direction of the last plying, so it is in the direction of the original twist. Very little plying is required in this last step.
The secret is to over-ply during the first plying. The correct amount of over plying is about three to four times the usual plying twist. For instance a medium size yarn spun Z with 3-plying twist per inch in the S direction, will need to be plied with 9-12 S twists. You must put in enough plying twist so that the plied yarn will twist back on itself. Checking the twist amount frequently is recommended. Let a short section fold back on itself. If it doesn't make the braided cable look, then there isn't enough overplying twist in that section.
You can learn do this visually by watching the pearls (definition between the plys), flatten out and become tight. It is also helpful to count the number of treadles, to keep from under-plying further in the bobbin. Many spinners will start passing the plied yarn in too quickly about midway through the bobbin, without enough over-twist to get a good effect from the cabling/second plying operation.
Another way to get a whole bobbin overplied is to make a simple S plied yarn and then run it back through the wheel one more time, in the same S direction as the before until it is over plied S. Whether you do this in one or two passes through the wheel this is all part of the first plying.
The second plying, the cabling is in the original direction, (the same direction as the single was first spun probably Z) it will be very lightly plied. In fact all it needs is about 1/4 of the original plying since the finished yarn is made of 4-plies.
For the second/cable plying, wind the overplied yarn into a ball so that you can ply from both ends or make up two bobbins of overplied yarn. Since the yarn must be so over plied, it can be snarly and difficult. Sometimes letting the over plied yarn set on the bobbin for a few days before doing the cabling can be helpful. You can also cable an over plied 3 ply for a 6 ply yarn. Or you can cable many styles of novelty yarns.