thanks +Jim Munro
So does this mean that the 302 is even more problematic than the 303?
Here's a scenario where someone would want to use such a redirect:
You have a blog post about football.
You link your keyword to the Wikidata entry on football (this lets machines instantly know what your post is about - it also shows that you mean European football, not American).
You use these linked-data rich resource pages to make your own webpages more understandable to search engines. But while these wikidata and freebase entries are rich in machine readable data, they are not so nourishing to human readers, so you want humans to follow those links to your own preferred or authored definitions of those words.
This is my understanding
of why some guys in the semantic-web may use 303s.