Thank you for your solutions, Huseyin, Wolfgang, but this still does not fix my problem with passing <font face="courier new,monospace">\setupnotation<font face="arial,helvetica,sans-serif">.  Why does Mark IV keep throwing the error “undefined control sequence”?  I have reinstalled ConTeXt and run both <font face="courier new,monospace">luatools --generate<font face="arial,helvetica,sans-serif"> and <font face="courier new,monospace">mtxrun --generate<font face="arial,helvetica,sans-serif">.<br>
<br>Sincerely yours,<br>Adam Khan<br></font></font></font></font></font></font>