Stain identification

Just trying to figure out exactly what this is.

It’s a little chalky to touch.
There is a patio above the stain
It looks like run off

And some good suggestions on removing Georgia cal from brick and stucco…

F9 Efflo on the runoff - protect the door

don’t waste your time or their money on the clay at base until they sod it or get some mulch there. First thunderstorm it’ll be back