When sending packages from eBay to some countries, America for example you have to add customs information to the package. The click and drop service doesn't seem to include this feature.
Xander Mindhorn commented
I had a look in my products area and saw something new, Harmonization code. I think that is what Lee Harvey is talking about, from looking at the help icon that is along side it, looks like it is for commercial products that need to be included on customs declarations?
Uther Doul commented
If you go to your settings , then templates, you can tick a box to include customs declarations forms. They can then be printed out at the same time as your labels.