from what I understand it is just so they don't waste p-tex. They have a bunch of yellow p-tex and a bunch of pink p-tex. So at one point they used pink for the base and just cut out the word "line" so that they yellow part would fit in. At that point you have a bunch of pink "line"s left over and a bunch of yellow bases with the perfect space to fit the pink "line". So at that point you just put the two together and you have wasted no, or little p-tex