Ten Code

Ten-codes, properly known as ten signals, are code words used to represent common phrases in voice communication, particularly in radio transmissions. The codes, developed in 1937 and expanded in 1974 by the Association of Public Safety Communication Officials (APCO), allow for brevity and standardization of message traffic. They have historically been widely used by law enforcement officers in North America, although the trend is away from their use in recent years with more departments discouraging the use of ten-codes and encouraging "clear" or plain language communications.
Some organizations and municipalities also use other codes in addition to the ten-codes. An example is the California Highway Patrol's use of eleven-codes.
Historic overview
Ten-codes were adapted for use by CB radio enthusiasts before its pop culture explosion in the late 1970s, thus many of the phrases, such as 10-4 and "what's your twenty" have entered everyday use in the English language. A popular fictional account of ten-codes in use among CB-communicating truckers may be heard in the 1978 movie Convoy.
In the fall of 2005, responding to inter-organisational communication problems during the rescue operations after Hurricane Katrina, The United States Federal Emergency Management Agency (FEMA) discouraged the use of ten-codes and other codes due to their high variability in meaning (see the November 2005 articles in External links, below).
List of ten-codes
The following list, given in ascending order and grouped by decade, illustrates the current usage of various ten-codes. Only a handful of them are standardized. Some are fairly consistent, while others (such as 10-40) can have completely different meanings, many of which are not listed here.
Presentation:
Multiple meanings for the same code are in a bulleted list
The first definition is the current APCO specification.
Popular alternate meanings follow.

10-0
use caution
Dead
Dead Body
10-1
poor reception
10-2
good reception
10-3
stop transmitting
change channels
10-4
message received, affirmative, ok, understood
10-5
relay this information to ___
10-6
busy
10-7
out of service
Ending tour of Duty
10-8
in service
On Duty
Beginning Tour of Duty
10-9
please repeat your message
10-10
out of service, off duty
negative
transmission completed
Fight In Progress
welfare check
10-11
animal problem
road-side check
talking too fast
en route
10-12
standby
visitors present
disregard
call in reports
at scene
check revocation
10-13
advise weather/road conditions, civilians present and listening
call-in resume
10-14
suspicious person or prowler
convoy or escort
10-15
civil disturbance
prisoner/suspect in custody
10-16
domestic disturbance
make pickup at ___
10-17
meet complainant
pick up papers at ___
urgent business
En Route
10-18
urgent
complete assignment ASAP
anything for us?
drunk
10-19
return to station
Returning from Scene
10-20
specify location/my location is ___
10-21
please telephone ___
10-22
disregard
report to ___
send blood technician
10-23
arrived at location/on scene
stand by on this frequency
status check
en route to call
sex offense
10-24
assignment completed
trouble at station
unit not available
direct traffic
10-25
report to ___
please contact ___
do you have contact with person
come in for traffic
officer needs help
10-26
detaining suspect (implying "please expedite")
check auto registration
ETA ___
disregard last info
phone residence
10-27
drivers license request
vehicle registration request
I am moving to channel ___
any answer
10-28
vehicle registration request
driver's license request
identify your station
missing person
10-29
arrests/warrants request
time is up for contact
10-30
unauthorized use of radio
danger/caution
special check at ___
juvenile
10-31
crime in progress
domestic disturbance
check for local warrants
suspicious person
10-32
person with gun
fight in progress
radio check
check NCIC
DWI test
10-33
emergency, all units stand by
officer needs help
disturbance at ___
fire
10-34
riot
frequency open (cancels 10-33)
help needed
trouble at jail
correct time
meet officer
10-35
major crime alert
confidential information
suspicious person
10-36
correct time of day?
Confidential information
10-37
suspicious vehicle
identify yourself
wrecker needed at ___
shoplifter
time of day?
10-38
stopping suspicious vehicle
ambulance needed
station report satisfactory
phone communications
vandalism
10-39
run with lights & siren
your message was delivered
false alarm, premises were occupied
contact officer
disturbance
10-40
run silent (no lights & siren)
false alarm, no activity, premises appears secure
please tune to channel ___
expedite
advise if available
suspicious person
dead animal
mental patient
lunch
10-41
begin duty
radio test
intoxicated person
debris in street
neighbor trouble
10-42
end duty
traffic accident at ___
malicious mischief
request dispatch times
10-43
information
traffic jam at ___
request criminal history
pick up passenger
armed robbery
rescue call
10-44
permission to leave patrol
I have a message for you
transmission received
rape
traffic accident (no injury)
10-45
animal carcass
pick up officer
fueling vehicle
all units in range please report
coffee break
traffic accident (injury)
non-injury accident (Kentucky)
10-46
motorist assist
lunch break
fuel break
wrecker
injury accident (Kentucky)
10-47
emergency road repair
call home
missing person
drunk driver
blood run
license plate check (Kentucky)
10-48
traffic control
request criminal history
runaway juvenile
use caution
10-49
traffic light out
en route to assignment
bathroom break
any traffic
serving warrant
10-50
accident Often referred to as a 10-50 PD (Property Damage), a 10-50 PI (Personal Injury), or (rarely) 10-50 F (Fire or Fatality)
no messages
break channel
auto accident with property damage
10-51
wrecker needed
auto accident with injuries
phone message
10-52
ambulance needed
fatal auto accident
message for assignment
alarm
10-53
road blocked
silent alarm
10-54
animals on highway
silent pursuit
car stop
10-55
intoxicated driver or DWI
security check
ambulance call
10-56
intoxicated pedestrian
warrant indicated
arrived at scene
10-57
hit & run accident
narcotics
officer at pistol range
10-58
direct traffic
wrecker
DOA
teleprinter message
10-59
escort or convoy
out of car checking violation
ambulance
bomb threat
10-60
squad in vicinity
traffic stop
what is next message number?
coffee break
assist motorist
10-61
personnel in vicinity
stand by for CW traffic
clear of traffic stop
weather conditions?
lunch break
10-62
reply to message
unable to copy, use phone
check for rising water
logged on/off
10-63
prepare to copy
make written copy
net directed to ___
need barricades
10-64
local message
message for delivery
net clear, resume normal traffic
field investigator
10-65
net message assignment
kidnapping
10-66
net message cancellation
bathroom break
10-67
clear for next message
prepare to copy
person calling for help
all units comply
10-68
dispatch message
repeat dispatch
switch channels
10-69
message received
any calls holding for me?
sniper
10-70
fire alarm
fire
fire followup
prowler
net message
chemical spill
10-71
Proceed with transmission in sequence
10-74
negative
10-76
enroute to location
fresh coffee
10-78
need assistance
major accident with injury
request wrecker
10-79
notify coroner
bomb threat
hit & run
10-80
pursuit in progress
bomb has exploded
tower lights out
on assignment
demonstration
10-81
breathalyzer request
stop for interrogation
reserve hotel room
officer ___ will be at your station
at vehicle maintenance
civil disturbance/riot
10-82
reserve lodging
stop for interrogation/arrest
traffic signal out
cover assistance
10-83
work/school crossing detail
call station
units stop transmitting
at radio shop
officer in trouble
10-84
advise ETA
checking officer status
my telephone number is ___
follow-up
broken utility main
10-85
arrival delay due to ___
prepare to copy info
my address is ___
loose livestock
10-86
officer on-duty
utility line down
10-87
pickup or prisoner transfer
pickup payroll check
dead body
10-88
advise telephone
station call
special assignment
true alarm
10-89
bomb threat
send radio repair
officer at academy
10-90
bank alarm
radio repair to be at station
officer at headquarters
false alarm
10-91
pick up prisoner/suspect
talk closer to the mike
prepare your inspection
vehicle fuel
bank holdup alarm
10-92
parking violation
your signal is weak
officer at court
10-93
blockage
please check my frequency
10-94
street racing
give me a long count
10-95
prisoner/suspect in custody
transmit dead carrier for 5 seconds
10-96
mental patient
detain prisoner/suspect
10-97
arrived at scene
test signal
possible wanted person in vehicle
known offender
officer at court
10-98
assignment complete
prison/jail break
criminal history indicated
officer at juvenile court
10-99
warrants/stolen indicated
officer needs assistance/held hostage
mission complete
bathroom break
10-100
bathroom break
dead body
10-200
police needed