[Symbiote]

English doesn't even fit in ASCII.

To write it properly, we need left- and right-facing single and double quotes, diareses and accents for words like naïve, façade and café, en- and em-dashes and the ellipsis.

Longer documents will require symbols like † and ‡, bullets and §. The currency symbols £, €, ¢ and ₹ are used by countries where English is an official language.

[microcolonel]

I can't even use symbols like that anyhow (I deal in USD, CAD, and NTD). I end up using ISO 4217 codes everywhere. You missed ¥ as well, for which I would use JPY or CNY.

[TazeTSchnitzel]

And English speakers need to talk about things from non-English-speaking countries sometimes!