Thank you all for your comments and explanations. One question to Akira-san,
though :
If you use -no-pdf option and apply xdvipdfmx to a created
.xdv file, you can see messages like
xdvipdfmx:warning: xetex-style \special{x:rulecolorpush} is
not supported by this driver;
Is there any way (perhaps through a command-line option to XeTeX) that one could obtain those most
usedful diagnostics using XeTeX in "standard" mode, i.e. without using the
"-no-pdf" option and without running xdvipdfmx explicitly ?
/Philip Taylor/
