I have Penguin editions and Modern Library editions of JA's works -- both of which offer footnotes that shed light on issues or items that come up in the novels.

For example, near the end of chapter 3, Sir Walter states that "Mr. Wentworth [the cleric] was nobody, I remember; quite unconnected; nothing to do with the Strafford family." The footnote in my Norton edition explains that "Wentworth was the name of the Earls of Strafford" (p. 17).

But in my other editions, notes such as these are located at the very end of the book, which is rather inconvenient; Norton places them at the bottom of the page to which they correspond -- much better!