Why is ≈ not a valid character entity for XHTML 1.1?
On a lark, I decided to put this one webpage I haven't yet published through the W3 validator. I closed one tag I had inadvertently left open and went from 380 errors to just two, one of them being ≈ is supposedly an undefined character entity. I've tried the webpage on a few different Web browsers and they all show the symbol correctly. What's going on here?