The arms of the four provinces of Ireland emblazoned on a green flag with a shamrock crest at its centre.
Logos used on the official match programmes from the 1920s to 1954, showing a single shamrock surrounded by an oval had no relation to the official jersey emblem.The only time an Irish jersey had a single shamrock was when the Ireland side toured Chile and Argentina in 1952 and Argentina in 1970, and in both series no caps were awarded. Although the use of the shamrock has been a constant, albeit with modifications to design, other elements of symbology have changed. In the early twenties, when the Irish Free State was established, the union was left in the position of governing a game for one island containing two separate political entities. A controversy ensued as to what flag should be flown at international matches. For a side that played both in Dublin and Belfast (the former being in the Free State, the latter being politically part of the United Kingdom) this posed a significant issue. In 1925 the union designed their own flag, incorporating the arms of the four provinces.