None of the online search engines really tell you what spam is or what they consider as spam. Neither do they really explain what a link farm is. All they really do explain is no cloaking, no backdoor pages or no hidden text/links. They say don't spam your site(s), but what is really spam? They really don't explain this and then just ban sites with out reason. This is why the big boys are always in the news for being taken to court!