Note, the iPod is not UL Listed in this picture from link supplied by Tom.

The backwards "R" then "U" is UL component recognition, meaning the components are UL Listed but the assembled device is not. It does not mean the assembled device is not safe, but has not been submitted to UL for testing/listing to obtain a UL Label and File Number. In order to obtain a UL Lable, UL needs to have a procedure already in place of a prior unit that was submitted and listed, or the 1st time guy submitting it works with UL to set up a testing procedure, pay all the fees, then a basis for future like products would be tested the same way, to obtain a UL Listing/Lable and File Number.

Note, I said UL Listed, not UL Approved. Contrary to the way people speak, there is no such thing as UL Approved. They approve nothing....they test things to a rigid standard procedure, product by product, and if it meets the criteria, it gets a file number and UL Listing, then the device can bare the UL symbol.

Note also the "CSA" marking, this is Canadian Standards Associates, the Canada equal to America's UL. Generally speaking for CE products, if an item made for sale in America has a CSA Lable, it is considered adequate and meeting the standards for safe sale/use here.

It's far more involved than this, but the basics are FYI.

Not having a UL Lable is not meant to imply there is anything wrong with the product. Look around your house, and you might be surprised how many items do not have a UL Lable. Next time your are at Best Buy etc, check out the packaging and you'll see more of same.