CAD stands for Computer Aided Dispatch. It is the software (combined with hardware) that dispatchers use to dispatch calls quickly and efficiently. So, in that case, a CAD number would most likely be a report number which refers to specific call ticket in the CAD software so the officer can reference it. Officers often ask for this number when writing reports. This number can also be called a CR number, or case report number. Hope this helps!I hear the Leav. pd asking disp. for a cad number, so what is a cad?