Two angles are needed to specify where a guitar neck points.
Viewed from the front
One angle is looking at the person from the front, where we could define 0 degrees as horizontal, and 90 degrees as pointing towards the ceiling. It seems that most rock people want 0 degrees, although I like 30 degrees or so, perhaps more.
Viewed from above
The other angle is the one that I’m curious about: Looking at the person from above, 0 degrees would be pointing to the player’s left, and 90 degrees would be pointing in front of the person. For this angle, it seems that 45 degrees is a good choice, because that lets one’s elbow rest against their rib cage (at least in my case). What is this angle, typically?