Can someone define 6 o'clock hold please?

Thru the years I’ve had “6:00 hold” described as “pumpkin on a fence post” for the various bullseye targets used. The round black target sitting atop the post front sight.
Where your bullets actually impact (hopefully in the pumpkin) is dependent on gun, sights, type of ammo, range and how your eyes see the target. Hopefully the POI is to RJ-spec otherwise you get to tweak something until it works for you.

I set all our pistols for picture #2 in you first post. To me the #1 only works at one distance w/ one diameter bullseye. Why would I want to set my sights so the POI is at some distance above the sight? I can see that for bullseye or another type of shooting where the bull is always at the same distance and is always the same diameter. But for general purposes I don't like it. And #3 covers up some of the target so why would I want to do that?