Thanks sort of right, but some of it isn't. I send fine art through the Post Office, UPS, Fed Ex, and and friend who works for a fine art museum and arranges shipping for antiquities.
If you send something by Registered Mail the PO will hold it for the signature of the addressee. This will proove that the addressee received / accepted the package but it won't guarantee that the PO itself doesn't lose the package. It also won't establish the value of the package. You can claim a value, but if you want to collect that value you have to be able to back it up. For instance, when I send a negative to be drum-scanned, if it's lost I'm potentially losing however many prints I might have sold from that image. If I plan to sell an edition of 100 images from that original, I've potentially lost the income of 100 prints. The Post Office's attitude, however, is that if I did not have 100 prepaid buyers at the time I sent off the negative, I've lost nothing, regardless of the value I claimed for the negative. I'd be willing to bet that, if someone lost a VIN tothe Post Office, they would want "proof" about how much the value of the car dropped (i.e., what were you offered for the car before the loss, and what were you offered after the loss) and how you know (i.e., they would want offers in writing).
This is a long-winded way of saying "Do not trust your valuables to the Post Office without knowing the ins and outs of the process."
