 These "frigates" were roughly mid-way in size between cruisers and destroyers.This was similar to the use of the term "frigate" during the age of sail during which it referred to a medium-sized warship, but it was inconsistent with conventions used by other contemporary navies which regarded frigates as being smaller than destroyers.During the 1975 ship reclassification, the large American frigates were redesignated as guided missile cruisers or destroyers (CG/CGN/DDG), while ocean escorts (the American classification for ships smaller than destroyers, with hull symbol DE/DEG (destroyer escort)) were reclassified as frigates (FF/FFG), sometimes incorrectly called "fast frigates".