Ch. M. Kieffer, "Afghanistan v. - Languages of Afghanistan", in Encyclopaedia Iranica, printed version, p. 507: "[...] 'Dari' is a term long recommended by Afghan authorities to designate Afghan Persian in contrast to Iranian Persian; a written language common to all educated Afghanis, Dari must not be confused with Kaboli, the dialect of Kabul [...] that is more or less understood by more than 80% of the non-Persian speaking population [...]"