I have posted to the above thread, I think, every character identified in the W3C Committee HTML 4.01 Specification . Purpose of these postings was simply to see which characters work on mudcat, and which do not.
For information on characters in general (especially how the unprintables should look), see Unicode, or consult the Online Unicode Handbook. Note that the Unicode charts are in order by the HEX entity number
Results were obtained using the English-US keyboard setup in Microsoft Word97 to prepare inputs, with Internet Explorer to view the results. Print results mentioned are with Windows 98/2000 default fonts, plus several additional, on an HP LaserJet 1200 in PostScript mode.