noun
registered mail to addressee in person; PD PR
A postal service term for registered mail that is delivered only to the named recipient, requiring personal identification. The abbreviation PD PR stands for 'Personal Delivery, Proof of Receipt'.
重要な書類は親展書留郵便で送ってください。
Please send important documents by registered mail to addressee in person.
Compound of 親展 (confidential, to be opened by addressee only) + 書留 (registered mail) + 郵便 (postal service).