banned from school property
Can a principle of a school ban a parent from school grounds when they have children attending that school?
Re: banned from school property
Is this a public or private school, and what grade levels are we talking about? If private, possibly. You need to study the code of conduct and rules and regulations of the school and whether the school has grounds for it and whether it complied with its rules.
Public is different. This is subject to attack since it is public property and there would have to be exceptional reasons for this, such as harm and or danger to the school population, or like reasons. In a public university setting there are codes of conduct you would need to read.
I would need more information to address it properly.
