Fanciful nicknames have been given to most of Chopin's Études from time to time, although Chopin himself never used nicknames for these pieces, and none are authentic. Only about three such nicknames are widely used: Op. 10, No. 5 "Black Keys"; Op. 10, No. 12 "Revolutionary"; and Op. 25, No. 11 "Winter Wind". A number of occasionally suggested nicknames are shown below.