This might seem like a really obscure question, but it's somewhat significant, because whether the city in Northern Ireland is called "Derry" or "Londonderry" is a contentious political issue.
I re-read Stephen King's It recently, and there's a mention of Derry being named after the city of Derry in Ireland. However, I have a memory of reading it the first time, in my teens (over 25 years ago) where the same sentence said it was named after Londonderry. As I said it's an obscure thing to remember, but I noticed it at the time because of the aforementioned political implication.
Is there an old edition of the book which calls it (i.e. the Irish city, not the Maine one) "Londonderry" or is it my faulty memory? And if I'm right, what was the reason behind the change?