दिए गए शब्दों मे से कौन सा शब्द confidential का पर्याय है?

Letters containing valuables e.g. cheques, drafts, policies, etc. are sent to the sections in a separate register named register of valuables. Letters containing important documents like service records, pension papers bills should be sent through a transit register through which their receipt should be watched. The register of valuables should be submitted to Audit Officer by the 5th of each month. The confidential letters are ordinarily received in double covers. The outer cover bears the official designation and the inner cover bears the name of the officer and is marked “confidential”. The letter should be handed over to the officer concerned. All the registered parcels and envelopes on receipt will be first checked by one of the markers of the Registered dak with the Postal List and the receipt acknowledged. The parcels and covers will be opened by the Daftary with due care. After necessary stampings, it will be passed to the markers who besides marking the section should also give postal registered cover.