Some Structural Engineers in the Philippines claim their building can withstand 8.5 magnitude

Why do some structural engineeers in the Philippines tell their clients the building/structure they designed can withstand certain magnitude of earthquake. In turn building owners would claim in social media/tv the same thing. Buildings/Structures are not designed per magnitude of earthquake as far as I'm aware. I'm curious how are they corelating to equivalent magnitude. My guess is this is their "layman" term to saying it's designed to code.