Pin line = illegal way to obtain pins (You dial a number, you enter a number, it gives you a pin), the pins you obtain from this only are valid for 3 minutes until they become invalid
6 month exploit = some "new" (new to me) thing that lets you turn the pinline pins into "legit" 6 month valid pins.
Some people sell pinlines, don't ask me how to get them, and trading pinlines on sythe is AGAINST THE RULES.