What Would a General Default Look Like?

So Republicans may have decided to raise the debt ceiling without conditions attached — the details still aren’t clear. Maybe that’s the end of that particular extortion tactic, but maybe not, because, at best, we’re only looking at a very short-term extension. The threat of hitting the ceiling remains, especially if the politics of the shutdown continue to go against the G.O.P.

So what are the choices if we do hit the ceiling?