My friend who monitors Santa Cruz says they mostly use plain English. So they say, on scene, available and what not. Even say traffic stops in plain English. But for when they do use codes
Police Radio Codes these can help.
A dispatch for a disturbance call would call for units by their id, and then use the penal code which is 415 with the location and info on the call.
A dispatch for something like a crash would be unit ids and the crash info in plain English.
Traffic stops are also in plain English.
Netcom is the dispatch center name I believe.
Code 3 responding lights and sirens.
Code 4 means scene is under control.
Code 7 means someone died.
Code 6 means someone has wants.
Females are often referred to as X (Xray)
Person description is often said in the format WMA (White Male Adult)
It would help to listen to understand how they operate, like when an officer does a traffic stop, he provides a plate, dispatch gives returns on the plate to check for wants, and if it's stolen(VC10851) and tells the officer that. Officer then runs the driver's license often in other departments by saying 10-27, 10-29 and then provides full name in phonetical alphabet form, and DOB. Once you know how things should be you can predict what's coming. Unit IDs also have meaning to the number and letters, the best way to learn what everything means is by listening enough, you will come to conclusions.