The ECB has published their 2011 rules for the Correspondent Central Bank Model – this is the system that allows debt instruments issued in one country to be used in another country as collateral to get funds from that other country’s central bank.
It’s mostly a procedural document but it does contain a discussion of something called “The Irish Variant” (p12), which refers to how Irish Mortgage-Backed Promissory Notes should be handled. These appear to be a form of IOU which Irish financial institutions can write and have them backed by their pool of mortgages — but to be able to sell the IOUs to anyone else, they need to have them further backed by the Central Bank of Ireland so they will be taken by other Eurozone central banks for credit to whoever buys them.
This facility is no doubt useful for the Irish institutions during the crisis and it appears to be an additional channel of liquidity for them on top of the guarantee scheme and the NAMA bonds. But among the interesting points about the facility is that it is not new — there are mentions of it going back to at least 2002. Here for example is the Irish Central Bank’s annual report for that year –
In 2002 domestic credit institutions collateralised Eurosystem operations mainly through the use of Tier One eligible assets. Significant use was made of domestic Tier One collateral; in addition the use of Tier One assets issued in other member states continued to increase. The use of Irish mortgage-backed promissory notes which are included on the Tier Two list also increased, underlining their importance to the local market.