I don't know. But if you follow the incredible and rare White Hat secret technique of writing your own content, they sure as hell can't detect anything. I can't tell you much more about it though, since it's almost impossible to find any information on original content. I heard it used to be common 40 years ago, but it pretty much doesn't exist anymore. Why write your own content when you can just steal it? It's an amazing technique, until the day it doesn't matter anymore and nobody can make any money anymore because there will be so much shitty content floating around that it will have no value at all.