Stats question net punting

How do penalties affect net punting?

If a returner returns a punt 80 yards but it gets called back because of a hold is the net punt taken from the spot of the hold or somewhere else?

I think it gets called back from where he caught the ball , so he gets 0 yards . If you notice the refs throw something down where the guy caught the ball then they minus the yards from there. I may be wrong though.

The penalty is enforced at the spot of the foul.

Most times, holds or illegal blocks are made just as the returner catches the ball but there is the odd time once the returner has broken a seam, someone on his team holds way down the field.

Basically, the refs feel that this is the point where he would have been tackled and therefore the penalty is enforced from that spot.

I understand the penalty implications, and the spot of the foul, my question is regarding the statistics of net punting and how penalties affect that.

Net yards of a punt = (distance of the punt) - (return yards)

The punt return ends at the spot of a foul and the penalty yards are not factored into net punting.

When a punt goes for a single, 35 return yards are charged against the net of the punt