how to interpret this, yay output? - eviltoast

reading “Build Files Exist” seems to suggest the package already exists, but it’s not, I think.

So what is “CleanBuild” and what do the options mean: [N]one [A]ll [Ab]ort [I]nstalled [No]t Installed

And is meant by (1 2 3, 1-3, ^4) ?