[elliottinvent]

Thanks for your input, I think you're right – it's deliberate, but seems like a pretty wasteful use of DNS TXT to me. Every SPF lookup is dragging that much bigger record with it too and it serves no real purpose for anyone other than the administrators of the example.com zone. It seems like a strange thing to put in this zone particularly because it's used in so many examples.

[Habbie]

I bet this was in before the SPF also went in. You should feel free to take this up with IANA, of course :)