I have always wondered too, cos kitties have no facial expression, lol... hard to read the tail, but I know just one where the tail is held up 90degree with the tip bent, but I only saw cats with very very long tail does that. All those with shorter tail or the stubby tail, it will be difficult to know. ET doesn't have very long tail in the 1st place, he never held his tail 90degree, and he sometimes flap up/down, sometimes swing left/right, sometimes just tap lightly, all sorts. I'm still trying to read his tail signal. His tail move when playing, when combing, when stroking. Anyway, to avoid trouble and getting scratch, I stop whenever I see his tail moving. :-(
I suppose one could get into deep discussion about this. I disagree that they have no facial expression, but most of it is in the eyes. When Zenobi bit me a day or two after I'd adopted her, her eyes showed pure blazing anger. This disappeared when I offered the back of my other hand to her. Her eyes softend immediately.
Missy, when I brought out my poor Zenobi's bed, became very excited as I carried it in. She was on the floor and I had it in my hands. She recognized what it was right off and started bouncing around quite agitated. When I put it on the couch she jumped right in.
Another time she thought I was angry and went to hide. I managed to get her up on the bed and started to brush her. I'm not kidding, but a big tear of happiness showed up in the corner of each eye, probably because she saw that I wasn't angry after all. I thought that maybe I was mistaken and that the tears were normal, so I checked the next few brush/pet sessions; no tears.
I'm going to keep my camera handy to see if I can catch different expressions. It's probably a long term project.
In the morning, Lickorish rubs against my feet (starting with the teeth and then down the body) and on the way down the stairs to breakfast, her tail is straight up and it quivers (the base of the tail is bushed up a little and the tip is shaking). She tries to rub my feet on the way down the stairs too, stops a few times for me to pet her, and keeps looking back to make sure I'm coming.
Other times, she's lounging on her condo or in the window, and she does this slow blink along with a head nod.
Squeek, is a little more obvious, she's all head butts and kneading biscuits. Lickorish has always been the more nervous kitty and to me, more rewarding when she shows her affection.
Cat behaviour can be confusing. I swear one off cats smiles. When she is on her back and purring while I scratch her tummy. Her eyes are closed tight she's vibrating hard and her lips are curved up. I really need to take a pic of it.
My ragdoll is always wagging her tail. She walks with it straight up and curved but anytime she is laying or sitting it wags like a dog. Even when she is purring and kneading... She wags it in her sleep too. Lol
Just thought of another one. Sasha does this running head but thing when I am sleeping. She charges me and hits my forehead with hers like a ram. I woke up a few times with a head ache from her doing that, lol.