sharp mark

[Itasan]

# (Hope this shows OK. two horizontal lines over
two vertical lines)
What do you call the above?
1. a sharp (mark/sign/signal/symbol)
2. a number (mark/sign/signal/symbol)
3. a pound (mark/sign/signal/symbol)
4. any other?
Never 'mark' or 'signal'?
Thank you.

[mykwyner]

I use sign or symbol.

[Itasan]

Thank you very much. 'pound sighn' or 'number sign'?

[mykwyner]

On a telephone it is called a pound sign, I guess that in other places its usage determines its name.

[Itasan]

Thank you, Mykwyner. Hot, isn't it?