Chassis cert question

What is an "undercut weld"?

My Demon used to have a cert tag and the bar above my head isn't even fully welded all the way around. They missed the top part where the halo loop hit the loop over my head cause of the roof being in the way. I thought all welds had to be 360*.

From what I was told if you gusset the bars then u do not beer to weld all the way around it. Not sure if that is true.