Is it okay to wear a slash back shirt to school?

My school is the same way. We have grade 9'ers at my school who have to wear uniforms, but no one else does. They belong to another school but are taking classes at my high school. Since our high schools are designated for grades 10-12, they stick out. Everyone else wears what they want. Short shorts, tank tops, etc. There have been girls at my school who have worn shirts with lace shear backs. You can see their bra, and it looks bad. I'd say wear the shirt with a tank or something underneath so that you don't show more than you want to.