Educators: Teachers are not to show or discuss their religious ideals with there students or with other staff. It is offensive to many and can cause backlash with your district of employment.
Students: Students are not to practice any form of religious practice when attending their place of learning. Government ran public schools are effected by these ideas. The only schools that have leeway are un-funded charter schools and religious based private institutions.
The Lemon Test: These are the three things that the U.S government has decided make a act cross the boundaries. Based on the 1971 case of Lemon v. Kurtzman, the Court will rule a practice unconstitutional if:
It lacks any secular purpose. That is, if the practice lacks any non-religious purpose.
The practice either promotes or inhibits religion.
Or the practice excessively (in the Court's opinion) involves