I had to mail a package to Berlin. It was actually a book that I was scared to take with me to Lebanon, in case my bags were opened and there was Jewish stuff to be found. It was a present for "K" in Berlin.
Because I wanted to mail a book, and pay the book rate there was a very specific way that the package had to be wrapped. The burocrat in the post office at length explained to us how it had to be and what we had to do in order to properly send it. To get this rate the package has to be openable in such a way that they can close it the same way without damage to the package. The point is so that they can easily open and close the thing to inspect that there are only books, and no letters or other stuff. The special rate is just for books.
So I went to the stationary store, and bought appropriate packaging, whcih ended us costing more than the shipping. The fact that I could not just use scotch tape and let them retape it was a real pain in the neck. They wanted velcro, or metal fastners, or magnets, or something like that.