CUCP#44 file format zone/fill: create a hatched zone on one board, plain
        old polygon on another and filled_polygon on a third

Igor2: (question)
> I see no difference in the gerber render, not sure if it's yet another 
> gerbv bug or really what kicad exported. Did you see any difference on the 
> on-screen rendering? 
> 
> If so, please make screenshots!
> 
> If not, we'll need to make some more research to figure what this setting 
> is for.

Karl Hammar: (answer)

The setting seems to be just about visual on screen appearance.

If the hatch lines are short, just inside the border,
no hatch lines at all, or if the hatch lines fill the zone.

Also, in kicad the zones arn't filled automatically as in pcb/pcb-rnd,
you have to manually request it.

So you right click on the zone border, a menu appears, choose zones, and
there you can Fill zone, Remove filled areas in zone etc.

This two stage approach is probably a performance optimization, make 
the zone, draw your tracks etc., then fill the zone. Polygons can be slow.
And the hatch thing is how the zone is presented when it isn't filled.