When I was in high school, I put the school badge on collar, name tag on the breast pocket. I had a name tag with last name. This picture shows some samples. Some schools tell the students to wear name tags and school badges. I wearied it and uniform there by school regulation,too.
People can tell who go to which school by looking at the name tags and badges.
I think there are several reasons why schools tell the students to wear name tags and school badges. Firstly, the name tags helped me to get to know fellow students name quickly. Secondly it makes student keen sense person. There should be other reason, too. Name tags shows he or her last name.