I have taken some time to sort out which of the smart quotes is used for what. Here is my result. First, let’s look at the smart quote alternatives in detail and in the order in which they appear in the list box of Scrivener’s Corrections dialog:
It is not very obvious, which of the alternatives is to be used for which language. The following table shows the Unicode coding of those quotes, their names and a selection of prominent languages in which they are used:
Some of the quotes are used in a language as an alternative to the primary quotes. Those are marked with “-alt” in the language name.
What I found remarkable is that the quotes in (4) and (8) appear to be identical, even the exact same Unicode characters. Also, I didn’t find any language for (5). I have used the following Wikipedia article:
https://en.wikipedia.org/wiki/Quotation_mark
And interesting that the quotes for the primary language that Scrivener is used for appear as number 7!
So far my little research on the subject. I am sure that the linguists and typographers in this forum can contribute a lot more!