It wasn’t that hard. I was able to pull up the study guide and found the Citizenship pdf. It is all there, but the in the title of the text definition(s) is that icky word, “generally”.
No wonder historians say the thing is “unsettled”.
It was a little deep for me, but I’m tired. You could probably enjoy the read. It isn’t long. I googled naturalization study guide and was able to search in the guide for citizenship requirements.
The governments has worded things is vague ways, for a long time. But perhaps that "generally" was to cover all bases. *shrugs*