Doggy Body Language: Wagging Tails

I decided to upload one of the first images I've been developing for a series of dog body language. This one is about Wagging Tails and their possible meanings. Not every wagging tail means the dog is friendly! So here is something to illustrate that idea! Hopefully some of you might think this is interesting!

I will upload more in this page: http://www.facebook.com/CaninusCuriosus
There is an album for the pictures translated to english!