Why do I keep on seeing uses of Glitch/Zalgo text despite it being banned?

I found out it was banned by looking through the Self Demonstration pages, one of them having Zalgo. Zalgo's page was basically "this is banned, everywhere". I presumed it was banned on the forums and the wiki, yet I still see uses of it with no repercussions.

I just want it to be clear: is it allowed or not, and if so, to what extent?

If you see it, report it via the Report Page or Holler functions. We prohibit in all parts of the site, but we can't read every post and edit.