What are these blue circles in the schematic?

[DDad]

I am looking at an AionFx Blueshift schematic and it has these blue circles in many spots, here highlighted in yellow.

What is that?

 

[owlexifry]

it's indicative of a connection/junction point - i'm pretty sure this is where one of the header pins would go, i.e. a point where one board meets the other

 

[Strat68]

Try and relate it to the parts near the header pins. I built one and it works well but it took diligence to maintain good build techniques with that. Any parts.