service code
| prefix
| service code | |
| el. | 勤务 码 |
| telecom. | 业务码; 公电密语 |
| prefix | |
| gen. | 字冠; 首标; 前束 |
| avia. | 地区号码; 电报报头 |
| earth.sc. | 词头 |
| math. | 前加号码 |
| radio.amat. | 前缀 |
| |||
| 勤务代码 | |||
| 业务码; ★ 业务代码; 公电密语 | |||
|
service code : 17 phrases in 8 subjects |
| Automobiles | 1 |
| Aviation | 1 |
| Computer networks | 1 |
| Electronics | 5 |
| Information technology | 2 |
| Space | 1 |
| Technology | 2 |
| Telecommunications | 4 |