Originally Posted by RobertM
1) Wide open eyes.
2) Dilated pupils (in case of a perceived threat), or very constricted pupils (as the cat tries to threaten back).
3) Flattened ears.
4) Tail lashing or straight tail with bristled fur.
5) Agitated meows that turn into growling and snarling.
6) Hissing voices and sometimes even spitting.
Well Robert, where have you been since March 7? Well, you are back and you are a winner
The topic appears to be one of behavior so I would have clicked on Cat Behavior in the box above and looked at the article names. Looks like the one entitled Cat Aggression Toward People would fit the bill and if you scroll down a bit you will find Warning Signs which lists the six warning signs you have listed. Funny, I don't remember any of these...