English (Ireland)

What is this English (Ireland) option when picking a language on your computer? does it mean that the spellcheck will recognise feck? That "so it will" or "so it is" at the end of a sentance does not get underlined in green? Does "Bertie" get automatically get capitalised? is an e automatically tagged on to the word "shit" does it automatically italicise "British justice" when it sees it in a sentence?
Does it always insert the word "crucial" into the phrase "another match for Irish soccer team" ?