sentences:  An Post issue "N" stamps at the current domestic posting rate, which allow posting to both the Republic and Northern Ireland; and "W" stamps at the current international letter mail rate.There were formerly "E" stamps for postage to within the European Union, but this postage rate has been discontinued.All three values were introduced in 2000 prior to the Euro changeover, however only "N" stamps were available for many years after that, and only by specific request at post offices; generally as special occasion stamps such as weddings or birthday celebration stamps which may be purchased significantly in advance of use.