This is a completely random question and has no affect on anything, but it's one of those things that makes me scratch my head and think, "Hmm, I wonder why they did that."
Why is there an image of a key stamped on the inside, upper section of the brawler bar on the PSC bumper?

 

This is an assumption, but maybe when they are being welded together, that is a "key" to the right place to install/weld?