I think there's enough content in my pages on ASCII and its extentions that I can now offer recommendations, and I have done so on the Wikipedia page "Wiki special characters" (to which I have also redirected the now-obsolete "Wiki ASCII codes page"). The server at Bomis does indeed send the header "Content-Type: text/html; charset=ISO-8859-1", so we can use those characters as recommended without guilt. The non-ISO characters like punctuation and math symbols and such will perhaps require a bit more research and some policy decisions.

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