Gazetteers generally list place-names in alphabetical order.
Several difficulties arise in dealing with Irish place-names.
First, Irish place-names often come from the Gaelic or Irish language, though some have been given English variations. Second, Irish place-names were sometimes spelled phonetically in family records and documents in other countries, because many immigrants did not know the accepted spellings. The phonetic spellings can vary widely from the accepted spellings because recorders sometimes misunderstood what the immigrants said. Finally, there are many places in Ireland with the same or similar names. A gazetteer may help you resolve each of these difficulties.