The Jargon File (version 4.4.7, 29 Dec 2003):

broken arrow
 n.

    [IBM] The error code displayed on line 25 of a 3270 terminal (or a PC
    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 center characters overstruck.

    Note: to appreciate this term fully, it helps to know that ?broken arrow?
    is also military jargon for an accident involving nuclear weapons....


The Free On-line Dictionary of Computing (30 December 2018):

broken arrow

    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.

   [Jargon File]

   (1995-02-07)


U.S. Gazetteer Places (2000):

Broken Arrow, OK -- U.S. city in Oklahoma
   Population (2000):    74859
   Housing Units (2000): 27085
   Land area (2000):     44.988256 sq. miles (116.519043 sq. km)
   Water area (2000):    0.609260 sq. miles (1.577976 sq. km)
   Total area (2000):    45.597516 sq. miles (118.097019 sq. km)
   FIPS code:            09050
   Located within:       Oklahoma (OK), FIPS 40
   Location:             36.036305 N, 95.783616 W
   ZIP Codes (1990):     74011 74012 74014
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Broken Arrow, OK
    Broken Arrow