Quiz: Remember the definition of mal de mer?
An accident involving nuclear weapons: The idea that this is a ''broken arrow'' never released is incorrect (1980s+)
The error code displayed on line 25 of a IBM 3270 terminal (or a terminal emulator emulating a 3270) for various kinds of protocol violations and "unexpected" error conditions (including connection to a down computer). On a PC, simulated with "->/_", with the two centre characters overstruck.
"Broken arrow" is also military jargon for an accident involving nuclear weapons.