5 ECB staff have further refined and expanded the methodology used to calculate the bond free float for the  aggregate of the four largest euro area countries that together account for around 80% of euro area sovereign debt and GDP. There are a number of methodological differences and enhancements compared with the bond free float shown in Cœuré (2018), op. cit.
These Guidelines were later revised in 2006 and are currently in the process of being reviewed to reflect the prevailing international best practice and to align them with the Proceeds of Crime and Anti-Money Laundering Act, 2009 (POCAMLA) as amended and the new Act on combating terrorism financing.