Diacritical marks lost on the net. How retain or recover?

[HAROLD WM KERSTER]

     A colleague wants to publish a biblio on the net.  Many languages
occur in the citations, so a few accents grave, etc. are present.  Transmission
via the internet strips off the marks.  Can anyone suggest how to retain
the marks or a way to restore them after transmission?
     If you are interested in this problem, let me know and I'll pass to
you any answers that seem workable.