Escluso means "excluding". In my opinion "Escluso D" means "excluding Germany", so that Ciao was sold all over Europe excluding Germany.
Take a look at 1979 C7E1T and 1979 C7V3T (just a few lines under your frame number) you can read "Solo mercato estero" (moped for foreign countries only) and "Solo merc. est. escl. D" that's for " Solo mercato estero escluso D" (moped for foreign countries only, excluding D).
As you can see there are some Ciao only for Swiss (CH) o France (F) as well ("Solo CH - F - D").