Goodreads Librarians Group discussion

I added a Librarian Note on this, but thought I'd see if anyone had any ideas here as well.

This is the 10th Anniversary edition of the book, which includes a one-page (unnumbered) author introduction, as well as a different cover. It uses the same ISBN as the first edition, though. At some point it was added as a different edition, but the ISBN commonality was flagged by another librarian at some point. What would be the best way of categorizing this one — right now it's a separate edition, which seems to make some sense, but thought I'd see if there's a standard practice for this sort of case?

It looks correct to me.