such that rendering programs DTRT for both ôòøfooôòù and ôòøbarôòù.
I don't see the problem, in principle. The information about what font should be used for what index entry is completely determined (and deterministic) by other known information. As Patrice says, though, it could be inconvenient to trace back the @syn*indexes and @def*indexes. I have no objection to adding the info explicitly in the XML (or whatever) output. k