These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Unfortunate Implications: In the early years (80-90's), the black kid in Urbanus's class was usually referred as "Het Negerke", which means "The Little Nigger/Negro". Of course, time passes and even the writers realised the name is wrong, so from 2000 onwards, the boy is giving the name of Botswana.
What Do You Mean, It's Not for Kids?? Although very popular with kids the comic often shows vulgar, sexual, violent or anti-establishment scenes or topics that aren't suitable for young children.
An Egregious example would be Urbanus in 3D, with lots and lots of nudity in 3D.