system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Gate] Why does it take a "source" chevron to activate the gate?

Wouldn't it limit the number of destinations, by requiring all gates to have one chevron that is specifically associated with it? Or is it a sort of "vector" marker that delineates the direction of the wormhole?
gpt
The point of origin symbol is unique to the DHD for every Stargate and it's always in the same place. This means we don't have to waste time finding out what the symbol is as Daniel did on Abydos.

As Daniel explains in the movie, the first six chevrons refer to specific points in space. Where those points intersect refers to the destination. The point of origin gives you, as you suggest, a fixed reference point.