The Douglas DC-3 is a fixed-wing propeller-driven airliner with tailwheel-type landing gear.
The Encyclopedia of Chess Openings is a classification system for the opening moves in chess.
The Four Knights Game is a chess opening that begins with the moves: This is the most common sequence, but the knights may in any order to reach the same position.
ICD-10 is an international statistical classification used in health care and related industries.
The Rosette Nebula (also known as Caldwell 49) is a large spherical H II region (circular in appearance) located near one end of a giant molecular cloud in the Monoceros region of the Milky Way Galaxy.