The lowest collateral the Fed will accept is AAA-rated private mortgage-backed bonds that are not on review for downgrade.

美联储所接受的最低质量的抵押都是AAA级别的私人房屋抵押债券，它们都不在被降级检查的行列。

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The first is that the Bank of England should extend its special liquidity scheme and lend banks directly whatever they need, accepting more mortgages, or mortgage-backed bonds, as collateral.

ECONOMIST: Housing market

The package allows Norwegian banks to swap toxic debt products like mortgage-backed securities for new government bonds, which can then be used as collateral for borrowing from the central bank.

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