I did not object to reverts to ″Z. Sich", but I would like to note that we talk of the Russian history here; in Russia until the turn of the 20th century the Ukr language was not in any form of official use, in fact it was not in use for writing at all (with singular exceptions). Moreover, it was widely viewed as a dialect of Russian vernacular in use in rural areas and by illiterate classes as a kind of patois. All the contemporary (18th century) documents pertaining to Sech refer to it as "Zaporozhskaya Sech" (i am using the common transliteration of Russian) for the simple reason of those sources being exclusively in Russian.