Board Thread:Inclusion debates/@comment-1678571-20200811174238/@comment-45692830-20200811191434

Again, it's discussing the idea that you have a general book and then within the book there's an "in universe non-narrative source", but the "in universe non-narrative source" and the book are not identical. Or, I guess, the sum of the "in universe non-narrative source"s within the book are not identical to the book. So novels are kosher, anthologies are kosher, but if we had a reference book that was generally out of universe but had an in universe non-narrative section that would not be kosher. It doesn't specifically address what happens if we have an out of universe book that has a narrative in universe section, but the same reasoning applies.

With that said, this was seven years ago, and I suspect that some amount of telephone or reinterpretation has happened in regards to this rule, so a more recent precedent might say something different for narrative sources.