Within the book, catch-22 is a military rule, the circular logic of which most notably prevents anyone from avoiding combat missions:
The phrase has become common to refer to any similar self-referential policy or any lose-lose situation.
Also see
Characters in the book : Yossarian, Orr, Milo Minderbinder, Chaplain Tappman, Huple, Hungry Joe, Kid Sampson, McWatt, Captain Black, Captain Flume, Chief White Halfoat, Colonel Cargill, Colonel Cathcart, Colonel Korn, Colonel Moodus, Corporal Whitcomb, General Dreedle, General Peckem, Lieutenant Nately, Lieutenant Scheisskopf, Major Danby, Major ---- de Coverley, Major Major Major Major, Major Sanderson, ex-PFC Wintergreen, Doc Daneeka, Gus & Wes, Pilchard & Wren, Nurse Cramer, Nurse Duckett, Dori Duz, Havermeyer, Luciana, Mudd, Snowden, Soldier in White, the Old Man in Rome, Nately's Whore, her Kid Sister, Snark, Stubbs, A. Fortiori, Kraft, Clevinger, Dobbs, Dunbar, Aarfy Aardvark, Appleby and The Man Who Sees Everything Twice.The sequel to Catch 22, Closing Time, was published by Joseph Heller in 1994.
Catch-22 is also a movie based on Heller's book, released in 1970 with a screenplay by Buck Henry. The cast included Alan Arkin, Art Garfunkel, Bob Newhart, Anthony Perkins, Paula Prentiss, Jon Voight, and Orson Welles. The film was directed by Mike Nichols. It was not regarded as a great success, earning less money and acclaim than MASH, which was released in the same year.