However, contrails formed from the exhaust of high-flying aircraft can persist and spread into formations resembling cirrus, cirrocumulus, or cirrostratus.
Cirrostratus at its most characteristic tends to be mostly of the stratiform species "nebulosus", which creates a rather diffuse appearance lacking in structural detail.
Stratiform and stratocumuliform clouds in the topmost region of the troposphere have the prefix "cirro-" added to their names yielding the genera cirrostratus and cirrocumulus.
