The galaxy map could be looked at, it's a bit inconsistent here and there...

I can't clearly remember but I will try anyway:

Some sector blocks do have names some do not. Or some sector blocks do have clear visuals and some do not.

And it just came back to me:

The alpha quadrant or gamma quadrant or whatever quadrant it was... it's name does not show up on the galaxy map.

So some "quadrant" names are actually missing from the galaxy map !