Terms for subject Communications containing extension

English	Chinese
conference telephone extension	会议电话分机
dispatching telephone extension with Voice Frequency VF selective calling	音选调度电话分机
Multipurpose Internet Mail Extension	多用途因特网邮件扩充
Multipurpose Internet Mail Extension	多用途互聯網邮件扩充
telephone extension	分机
transfer extension for train radio dispatching	列车无线电调度转接机