@nickmofo I once mailed a diploma to a friend (I made it myself to make up for the one he had lost. Long story). I wanted to mail it anonymously in order to make it a surprise, but also make sure that it got delivered by hand, so I went to the post office and paid extra to have it certified.

Sadly, it turns out certified mail can't be sent anonymously. I had to write my name and address on the envelope, but that was not all. I asked the postman: “Please don't bend it. It's a diploma.” What did he do? He picked up a pen and wrote on the envelope: “Do not bend. Contains diploma.”