I think these reference materials are more about how they’re well-characterized, right?

It’s peanut butter, sure, but it’s not meant to be the peanut butter or even represent any particular peanut butter.

Instead, it comes with a detailed document describing all of the kinds of measurements you could take on it and their expected results. If you’ve got a peanut butter testing machine, you can put some in there and make sure it spits out the same result.

So, you’re not comparing any peanut butter against it, just your machine’s results against the results expected.