Occasionally Fleetway mentioned their rivals (The Beano and Dandy mostly) in their comics. I recently found another one from a 1991 issue of Buster. Here in a X-Ray Specs strip Carl the Creep decides not to "waste his time" on The Dandy! And yes - they actually wrote 'Dandy', which surprised me as I'd have expected them, if they were to include it, to call the comic something along the lines of 'Dondy' or 'Dundy'. I don't think D.C Thomson ever retalliated to any of Fleetway's mentions to them, I don't recall ever seeing Buster or Whizzer and Chips mentioned in The Beano or Dandy, but I could be wrong. Anyway, here is the full strip, as illustrated by Mike Lacey.
I covered a similar incident to this one last year, when Bernie Banks accidentally walked into The Beano! Here's a link: