Assuming, you're talking about Balltimore City.....
10-1 signal check
10-3 poor signal
10-4 aknowledgement, yes, okay
10-5 no aknowledgement
10-6 standby
10-7 out of service
10-8 in service
10-9 repeat last tranmission
10-11 meet me at __
10-14 non emergency prisoner transport
10-15 emergency prisoner transport
10-16 backup request
10-17 phone station
10-18 Go to district station
10-25 stopping suspicious vehicle
10-26 switch to citywide channel (talkgroup)
10-27 drivers liscenes info request
10-28 request vehicle registration info
10-29 check criminal records
10-30 wanted (person or vehicle)
10-31 crime in progress
10-32 sufficient units on scene
10-33 emergency
10-34 civiel disturbance
10-35 major crime alert
10-36 description
10-37 request tow
10-38 request ambo
10-39 police vehicle disabled
10-40 request crime lab
10-41 request impound truck
10-42 request animal shelter
10-43A traffic signal out
10-43B traffic signal red out
10-43C traffic signal not changing
10-43D traffic sign down
10-44 request permission to __
10-45 permission denied
10-46 permission granted
10-47 negative
10-48 affirmative'
10-50 helicopter landing
10-90 looting
10-91 shooting
10-92 continued looting
10-93 continued shooting
signal 13 Officer needs assistance (urgent)
signal 30 property damage accident
signal 31 personal injury accident
signal 32 accident with fatality
Baltimore Co. uses the expanded apco codes.