Acceptable Targets: Of course, the long-runners which make up the bulk of the blog's grist and for some reason animals with any level of anthropomorphism (mostly due to the evident threat the overthrowing of humans by animals with sapience proves to Josh).
Josh only ever discussed Mallard Fillmore on the blog once, to note the irony of a comic discussing rum-free eggnog running right when the strip's author was arrested for his second DUI. The insane frenzy of political bickering in the comments section led to him vowing never to do it again. A few years later, he completely banned all discussion of that strip on the site due to the trend of every comment about Mallard Fillmore spawning flame wars.
Politics in general is very touchy and generally frowned upon, with warnings to take such things elsewhere. This Family Circus comic from October 2008 touched off a major firestorm even though the comic itself wasn't about politics - it just happened to have Dolly dressed up as Sarah Palin for Halloween, and Josh made a remark about it since nothing else in Family Circus ever seems remotely topical. It's one of the few times that Josh has created a new topic thread to excoriate the offenders for their bad behavior.
Hilarious in Hindsight: Josh said this about Dagwood's suit "If you donít want to draw attention to your status as an ancient relic from another decade, it may be best not to build a strip around the fact that your main character usually struts about in an outfit that nobody in living memory has worn outside of the most formal situations" Cue a year or two later, this exact suit is worn by the Eleventh Doctor who not only made it work, (While fighting monsters and running from explosions no less) but also made it fashionable amongst fans (Increasing bowtie sales by seventy percent)
Memetic Mutation: "More zippers, mule!" a line from Apartment 3-G, has spread to other blogs.