Hello, \tracinglostchars is ignored: % luatex --ini \catcode`\{=1 \catcode`\}=2 \catcode`\^=7 \tracinglostchars=1 \font\f=cmr10\relax \f \shipout\hbox{a^^df} \end Version: beta-0.70.1-2011061416 (rev 4277) The message "Missing character: There is no ^^df in font cmr10!" is not printed in the .log file unlike TeX or pdfTeX. Yours sincerely Heiko Oberdiek