| Subject | English | Chinese |
| telecom. | Battery feeding, Overvoltage protection, Ringing, Supervision, Code, Hybrid circuit,Test | 用户线基本动能馈电，过压保护，振铃，监视，编译码,2/4线转换， 测试 |
| tech. | code ringing | 编码信号振铃 |
| IT | ringing code | 振铃码 |
| telecom. | ringing code | 呼叫信号码 |
| tech. | ringing code | 呼叫信号电码 |