1080. Treatment of secret and confidential papers.
- Documents requiring special precautions to prevent unauthorised disclosure of their contents shall be marked by a responsible officer as "Secret" or "Confidential" according to their respective importance. When sent by post they shall be enclosed in double cover: the inner one shall be sealed and marked "Secret" or "Confidential" and shall be superscribed with the name only of the addressee, while the outer cover shall bear the usual official address and shall not be marked "Secret" or "Confidential". "Secret" or "Confidential" documents shall always be sent by registered post and secret papers should in addition be sent "acknowledgement due".
