Since the majority of legal links / READMEs I've found when browsing icon sets refer me to the general GPL / LGPL (as opposed to a specialized version of some kind) when I'm looking at license restrictions, I'm having a terrible time trying to figure out what would constitute source code, linking, etc. when it comes to images and / or icons. One specific example: under section 5 of the GPL, modifications must carry notices in the source code. . . how do I do that with an image? I guess I could try to find a few unused bits and encode my modifications in there (steganography, anyone?), but somehow that doesn't seem like what the license is shooting for. There are also other sections in there where I have no idea how to begin to comply with. Thus, I'm really confused. What exactly are the implications of using GPL and / or LGPL licensed images in something that isn't itself GPL'd? Specifically, I'd like to know what using GPL icons in an iPhone application might mean from a legal point of view. It feels like I'm missing something obvious here; any enlightenment / references would be appreciated!