The combined actions of the world’s central banks on Wednesday smack of a real fear that the world’s financial system is in trouble.

Injecting liquidity — that is lending money to banks — when short-term interest rates rise is perfectly normal in this age in which central banks target interest rates.

What is not normal is the Fed using auctions “to inject term funds through a broader range of counterparties and against a broader range of collateral than open market operations.” That move, the Fed says, “could help promote the efficient dissemination of liquidity when the unsecured interbank markets are under stress.”

Or, as a senior Fed official — that’s what the Fed wants him called — told reporters, “This is not about particular financial institutions, with particular problems. It is about market functioning.”

The Fed will lend money to banks based on almost any asset they own, even ones that are not liquid at all. That will include some of the more exotic loans and securities out there.

Investors, it appears, love it. The stock market opened sharply higher, reducing the losses that came yesterday after the Fed cut interest rates, but not by enough to satisfy Wall Street. This move is taken as evidence that central banks are determined to rescue the system, whatever it takes.

How much will the Fed lend against illiquid assets? It has a public list, already in use in discount window lending. You will note that it allows the lending of up to 85 percent of the face value of AAA-rated collateralized mortgage obligations, if there is no observable market value. There are some C.M.O.’s out there that have not yet been downgraded but that might not bring that much in a sale.

I’d love to see which assets are pledged, and how much the Fed lends against them. But the Fed won’t disclose those facts. Nor will it let us know which banks borrow using the new facility.

(This post was updated after Fed briefing for reporters.)