The post office is changing the requirements for where you can place the address on a flat sized mail piece (Flats are usually larger than 6-18"x11-1/2") For most of the magazine style pieces that we produce we will now be required to print the address upside down.
The new location choices are: Upside down or sideways on the bottom half of the front cover or right side up or sideways on the top half of the back cover. The changes are a bit more complex than that, but that is the gist of the change.
We have a bit before this goes into effect, this won't be a requirement till March 29th, 2009.
Federal Register Notices