When my DS first moved to the elementary building from the kindergarden building (1st grade) he , being the strong willed child that he is, started the year with testing the limits of his new teacher. After several days of notes home and phone calls I finally told her that DS could be made to walk the fence every day for the rest of the year, his tokens taken away (which he thought was pointless for cheap little quarter machine toys) for bad behavior, etc. and he wouldn't change his behavior until a real punishment was administered. Told her next time to send him to the principal and have him paddled or since I am only 5 minutes away to call me and I'd come paddle him myself. Needless to say, a few days later I get a phone call, tell boss I'll be right back, drive over to the school, borrow teachers paddle, took him to the office, paddled him 3 swats on the behind, took him back to class. The teacher (who by the way is a veteran teacher and has teenagers herself) was probably as upset as DS was that he got a spanking. She took him aside and told him how much she loved him and what a sweet and kind spirit he had but that he had to behave in class and not be disruptive. That she knew that I loved him and wanted him to have the best education possible, etc.
Never ever have had any more problems with DS at school. Being a strong willed child, testing the limits, in his mind it just had to be reinforced that if you do this, it equals this and this is not fun. He didn't mind the walking around the fence in recess (standard punishment) and would have had to the entire year had I not gone and paddled him.
If he did something that merited a paddling, I wouldn't have a problem with his teacher or principal paddling him on the bottom and he knows that if that is ever the case he will most likely get another when he gets home.
Wanted to add, understanding a child's personality goes a long way in what type discipline they will respond too. In DS case, talking to his friends when he should be working outweighed the punishment of walking the fence or having his token taken away.........they didn't cause him enough physical discomfort as the fun he was having chatting with his buddy, etc. When it was reinforced that you will be spanked for the continued behavior the physical discomfort aspect changed and so did his behavior.