for official use only

基本解释

They had a mail service, although it was for official use only.
建立了邮政系统，虽然只供官方使用。
CUI replaces 100-plus disparate categories of sensitive but unclassified information labels - such as 'for official use only' and 'law enforcement sensitive.
CUI取代了先前的100多种不同非保密敏感信息分类，诸如“仅官方应用”和“法律强制敏感”。
www.etiri.com.cn
The Jan Sangh in 1963 launched a violent agitation for abolishing English not only in official use but in shop signs, street signs and even car number plates.
1963年印度人民党前身加桑党发动了一场暴力运动，意图不只要废止官方使用英语，一般商家、车号牌等也不能使用英语标示。

They had a mail service, although it was for official use only.
建立了邮政系统，虽然只供官方使用。
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