| A | Residential | Inside Electrical |
| B | Industrial | Inside Electrical |
| C | Commercial/Institutional | Inside Electrical |
| D | Energy Management/Power quality | Inside Electrical |
| E | Lighting Maintenance and Retrofit | Inside Electrical |
| F | Marine | Inside Electrical |
| G | Sign | Inside Electrical |
| H | Motor Repair | Inside Electrical |
| I | Instumentation/Testing | Inside Electrical |
| J | Service-Residential | Inside Electrical |
| K | Service-Commercial and Industrial | Inside Electrical |
| Teledata | Teledata | Inside Electrical |
| S | Substations | Line |
| T | Transmission | Line |
| U | Underground Distribution | Line |
| V | Overhead Distribution | Line |
| W | Distributed Generation/Cogeneration | Line |
| X | Line Clearance/Tree Trimming | Line |
| Y | Communications/Data (External) | Line |
| Z | Street Lighting/Traffic Control | Line |
| 1 | Communications/Data (Internal) | Systems |
| 2 | Fire Alarm/Life Safety/Nurse Call | Systems |
| 3 | Building/Automation | Systems |
| 4 | Industrial Controls | Systems |
| 5 | Security Systems/CCTV/Access Control | Systems |
| 6 | CATV | Systems |
| 7 | Home Automation/Networking | Systems |
| 8 | Sound/Public Address/Intercom/Paging | Systems |
| 9 | Photovoltiac Systems | Systems |