AV>>> without any characters from the 0x80...0xFF range.
BF>> Why?
Why indeed...
AV> The working language of this echoarea is English,
Yes. But that does not mean that only English names are allowed. If we would allow only English names, we would have to ban Janis Kracht en Joe Delahaye. "Kracht" is Dutch and translates to "Force" in English. "Delahaye" is French and translates to "Fromthehague". So they would have to write as "Janis Force" and "Joe Fromthehague". Of course we don't ask them to do that. Just as we do not ask you to change your name to "Alex".
AV> and all 26 capital and 26 small letters of English alphabet reside in AV> the 0x40...0x7F range.
The English alphabet is larger than that. Björn already pointed out the currency sign for the Pound Sterling: £. x9C in CP850, xA3 in Latin 1 and codepoint U+00A3 in Unicode.
Characters with a diaresis ARE used in English."Naïve" was already mentioned. It is often written as "naive" in US English, but that does not mean the version with the i with diaresis is incorrect.
English also allows the diaresis in names. Noël Coward was already mentioned. I add Emily Brontë.
