For my Christmas present this year I hope someone fixes this website - or shuts it down. This symbol does not mean "approximately equal to" - that's
≈
This symbol means "isomorphic to", or "congruent to". I cannot stand another year with this misinformation ruining my Google searches for the Unicode and HTML for "approximately equal" to.
https://www.fileformat.info/info/unicode/char/266f/index.htm