European charity - relief for donation?

Since 2010 the definition of charity has been expanded to include certain European charities. I specifically wanted to know whether a UK individual could claim higher rate relief on a donation to the Uffizi in Florence. Leanne at the charity helpline (084530202033)  told me that only 6 European charities had subscribed to HMRC's

scheme ( the participating charities have to meet the revenue's criteria for acceptance). She would not identify those charities which do qualify as, "this information is not in the public domain" She suggested I contact the overseas charity directly.

 Shouldn't this information be in the public domain? Can anybody point me towards the Uffizi's position ?