Since I also need to be able to switch to a Non-Roman script I do need a font switch here (that's also the reason why I use XeTeX and MKII.) Anyway when I use \Mywordstyle inside the FormatSpan like this:\Mywordstyle is a font switch: \def\Mywordstyle #1 {\switchtobodyfont[GentiumItalics]{#1} \switchtobodyfont[Gentium]}Do you really want a font switch, isn't a style switch enough in your case from roman to italic and back.