"Toller" wrote in message

As you observed, nearly all are ground down.
Some say that is wrong because things falling down will hit the
hot/neutral rather than just the neutral.
There is some sense to that, but ground up looks wrong to most people
since it is not common.
Neither is "proper". Probably best to do whatever the rest of your
outlets are.

Some appliances, like air conditioners, have plugs on the ends that will
hand better if the pin is up. They are designed that way as that is now
considered the proper way to orient the receptacles, at least in commercial
applications. . There is no code covering orientation.

Seems like most NEMA publications show the pin up on the 5-15 configuration.
I just looked at my GFCI in the bathroom and the test and reset buttons are
engraved in both orientations.