The normal rule of thumb is that when it comes to Dublin postal codes even (including 6W) = southside, odd = northside. The exception that I know of is Dublin 8 which includes Parkgate Street (as far as Benburb Street), Conyngham Road (?) etc. and some or all of the Phoenix Park including the postal addresses (i.e. Áras an Uachtaráin, US ambassador's residence, some or all of the gate lodges etc.). Are there any other exceptions to the "rule"?