The Year 2000 RSGB IOTA Directory contains a complete review of all the Islands that do or do not qualify for the various IOTA references. The effect on the EI / EJ Islands is shown below. Now, there is a definitive list of Irish Islands and what they count as.
There are 5 IOTA references that cover all the Islands of EI / EJ.
They are EU-115, EU-121, EU-006, EU-007 and EU-103.
The main Island of Ireland.
Any Islands that do not qualify for any of the other groups are covered by EU-115. The main ones are :
County Clare = Scattery Is.
County Cork = Whiddy Is., Ballycotton Is., Dursey Is., Sherkin Is., Ringarogy Is.
County Donegal = Cruit Is., Inch Is.
County Galway = Turbot Is., Omey Is., Lettermore Is., Gorumna Is., Mweenish Is., Lettermullen Is.
County Kerry = Valentia Is., Puffin Is.
County Mayo = Achill Is., Achillbeg Is.
County Sligo = Coney Is.
County ??? = Spanish Is.
EU-121 The following Islands qualify for EU-121 :
County Clare = Mutton Is.,
County Cork = Bear Is., Clear Is., Fastnet Rock, Long Is.
County Donegal = Aran Is (Arranmore), Tory, Owey Is, Gola, Inishbofin, Inishdooey, Inishbeg, Inishtrahull,
County Dublin = Lambay, Irelands Eye, Dalkey Is.
County Galway = Inishbofin, St. Macdara's Is., Croaghnakeela Is., Slyne Head, Cruagh Is., Inishshark,
County Kerry = The Skelligs, Deenish Is., Scariff Is., Magharee Islands,
County Mayo = Clare Is., Inishturk, Caher, Duvillaun More, Inishkea North and South, Inishglora, Kid,
County Sligo = Inishmurray,
(The Stags are also listed. I found 3 "Stags" on the map that I have. They are "The Stags" in Cork, "The Stag Rocks" in Donegal and "The Stags of Broadhaven" in Mayo. At present, I'm not sure which is the one that qualifies....EI7GL)
EU-006 Aran Islands. The qualifying Islands are Brannock Islands, Inisheer, Inishmaan, and Inishmore.
EU-007 Blasket Islands. The qualifying Islands are Great Blasket, Inishtooskert, Inishvickillane and Tearaght.
EU-103 Saltee Islands. The qualifying Islands are the 2 Saltee Islands.