I have some understanding of general electronics but now I want to learn about actual electronic schematics. For this I look at some complex reference designs to somehow get an understanding because like this I usually learn best.
I came across this reference design where I cut out a part that I simply do not really understand. This shows the actual power/dc-connector input to the circuit.
However what I do not really understand are the voltage line arrows (like DC_IN). Since there is already the dc connector (PJ1-021) where pin 1 should be the voltage/power-in line why is there another red DC_IN arrow that points into the circuit (on the upper left)? I would understand if this arrow would point out of the schematic to show that it is used somewhere else. Is this arrow direction a mistake or am I understanding something completely wrong here?
And if this is not a mistake where does this 12V come from if not from the dc connector (PJ1-021)?