No they're saying that after you cover it up, that potatoes will form off the stem part you covered up.
Kinda like when you cover up tomato stems with dirt, roots grow off of that covered stem.
Thanks, no one had explained that to me. I had come to the point I thought that must be it, but needed to know for sure if that was it.
Growing up, we had potatoes in our garden but I never saw either parent heap more dirt on. Once the seed potatoes were buried nothing happened after that until it was time to dig potatoes. If they kept covering the growth, I never saw it. Remember, I hated that garden due to dirt. I've written before that I came home from college and dad asked me to go to garden and get carrots and I asked him what those plants looked like and he said he was a failure about teaching me about the garden.