I have been replacing outlets in my new house (The old owner painted over all of them. In fact, some covers had no screws - they were being held on by paint!), and I ran into something strange.
Most of the outlets had two black and two white wires. I am nearly sure this is part of a parallel wiring arangement in each room. However, one outlet in one room had three black and three white wires.
I haven't touched this one yet. Does this mean that this outlet has a main feed in to the room and then splits off in parallel on each side?