Is there a code requirement that receptacles be installed using pigtails?
Example: an outlet box with two 12-2 cables and a receptacle. Can you just
wire through the outlet (use all four screws), or must you create pigtails
for the conductors, thus using only two screws on the outlet (plus the
ground of course). I am sure that wiring thru was permitted 5 years ago and
even more recently, but things change.