Disciplining Children: How far is far?

As a stay at home mother, I tend to look up different topics online. I happend to one day look up discipline. Which honestly prompted me to to write this blog for you. Parenting has changed so much over the years, everything from the methods used for teaching, right down to disipline has changed. What made me realize this, was a discussion I had with my 11 year old son. For 11, he is a smart child. I just recently decided to sit down and talk to him about things he was learning in school, and what I found out shocked me. In schools where I am located, they teach children that certain methods of disipline are deemed as child abuse, and that if their parents do any of these forms of disipline to them, that they are to call the authorities. I was appalled by what I was hearing coming from my son, not because he was telling me this, but because the school system was teaching them these things. When a parent takes care of their child, to me it consists of displine, structure, food, clothing, shelter, water and last but not least love. When the school teaches your child that disipline(some forms) are not legal, your child then starts thinking they can get away with much more than they actually can. I think of it like this. The methods of displine back when I was younger as I am sure many others out there consisted of this, a spanking, kneeling in the corner, or grounding to your bedroom for the day/evening. Now when talking to my son, I brought up a few of these things and asked him what the school was teaching him in regards to these few things. He said and I will quote this "Mommy, they say you aren't allowed to spank me on my butt if I am bad". Now I don't spank my children because I really don't believe in it but what is the school teaching our children if they are telling them, that we as their parents aren't allowed to do certain forms of disipline? Times do change, but just how far is too far when it comes to disipline with children? As I searched the web looking for tips and advice to help the parents out there I came across an article that I found to be helpful with tips and advice on how to deal with some situations that in the past were able to be handled diffrently than they are now.
Discipline Tactics Article:(Copy and Paste link in browser)
http://www.webmd.com/parenting/discipline-tactics