Radio codes and acronyms promote brevity, clarity, and some protection, but lists appear in many books. Therefore, police should say over the radio only what must be said. They should avoid details that can be relayed later during a personal meeting. They should also avoid using the names of officers over the air, especially if they are undercover or detectives. They should also avoid broadcasting street names and addresses when working sensitive operations and should avoid all references to special enforcement areas. Other measures should include using simplex, low-power communications for car-to-car and undercover details; use frequencies that are out of band; and use a wire-connected telephone for communications requiring strict secrecy. Police should also be aware that cellular mobile telephones do not offer secure communications. Photographs