Reader danjack requested this, and since we're such a full-service blog here, I will oblige. This is the first in a series (of indefinite length and regularity) explaining the context behind, using Dan's term, "meta-messages." A meta-message is where a comic book writer comments on/references the work of another comic book writer in their comic. Each time around, I'll give you the context behind one such "meta-message."
Today, we have one of the most famous "meta-messages," courtesy of John Byrne.
In Uncanny X-Men #146, by Chris Claremont and Dave Cockrum, we saw this scene between Arcade and Dr. Doom...
Well, in Fantastic Four #258, John Byrne countered with the following scene, explaining that that Doctor Doom was, in fact, a Doom-bot.
So that was the "meta-message," Byrne felt that Claremont did not treat Doom well in the guest appearance (under the theory that, if you're using characters from another book, you should treat said character respectfully) so he explained that that was not the REAL Doom.