A spurious question today, now gone, was tagged mathworld, which led me to look into the tag. It had only one question, and I considered removing the tag from the question. The question was about code found on the MathWorld site that no longer worked in the then current version of Mathematica. I did a general search for "mathworld" and found among many questions that simply cited MathWorld for some bit of mathematics, there were some about having trouble getting code from the site to work.
I looked at some of the questions and thought a bit about the tag. I came to the idea that it would be nice to support MathWorld, and that people who came to our site looking for help with code found on MathWorld would find a mathworld tag useful.
So I wrote a wiki description and tagged a few questions, which you can review. Before going further, I thought I should ask the community whether there is a consensus that such a tag is a good thing. At this point, it can be easily undone.