This has been one of my favourite wikipedia pages for a long time. It's a shame that it's so hard to search through.

Detexify allows you to search by drawing math symbols:

http://detexify.kirelabs.org/classify.html

The HTML version seems to be searchable, so one just has to input that into one’s favourite browser text search field?

I'd also like to point out these articles:

* https://en.wikipedia.org/wiki/Latin_letters_used_in_mathemat...

* https://en.wikipedia.org/wiki/Greek_letters_used_in_mathemat...

* https://en.wikipedia.org/wiki/Aleph_number

* https://en.wikipedia.org/wiki/Beth_number

* https://en.wikipedia.org/wiki/History_of_mathematical_notati...

I was very happy to see the tilda in the list and defined. I have been signing most emails for more than 5 years with ~Keith as I think that this accurately conveys that email poorly approximates my intention. After signing emails this way many coworkers now put prefix symbols to their sigs because they think it looks cool, but I suspect only the geeks have an inclining as to why I do it.

I don't fully understand the relationship with that method of signing and the mathmatical notation

I don't think you mean that if you perform a series of transformations on the body of your message you will get Keith

I don't think you mean that your body of text is approximately equal to Keith, or Asymptotically equal to be precise.

I don't think you mean that your body of text is essentially the same as you.

Though all of these are somewhat close to what a signature means, I suppose.

I've seen the ~Name notation around a fair number of times, I assumed it was just a form of notation.

It doesn't cover the angle symbol with a small "s" in the angle. Never known what that is!

I have never seen this notation used, but perhaps it is mean to represent steradians (the unit of solid angle)?

Not sure... But there is a Unicode symbol for it:

http://www.fileformat.info/info/unicode/char/299e/index.htm

P.S. thanks for the new term - steradians! It's amazing how many terms are in the mathematically universe :-)