Term used to describe a ruling by the American High Court
on how secular
the symbols and activities of a religious celebration need to appear before they can be permissibly displayed at a public school
Essentially, keeping to the principles of separating religion from government activities, public schools cannot have overtly displayed religious symbols, like creches or menorahs, unless they are part of something that in its totality appears secular. A majority of justices have considered Christmas trees as having little religious significance and can be displayed. However a display of Jesus's cruxification would not be suitable during Easter.
The ruling came from Florey versus Sioux Falls School District, which upheld the school board's policy of giving students some awareness and appreciation of how religious heritage has shaped social, cultural and historical developments. Students should be given some exposure to religions in an unbiased and objective manner, and in the context of education.