A high school is setting some limits what kind of hooded clothing may be worn in classrooms, and some students are not fond of restrictions on a popular fashion.

Last week, students at GlenOak High School were told they no longer would be allowed to wear zip-up hoodies during classes, because wearing coats in classrooms isn't allowed.

Renee Starn, who with her twin sister Natalie helped organize a protest by urging students to wear hoodies this week, estimated that half of GlenOak's students wore hoodies Tuesday.

Mark Hartman, principal of the school that has about 2,200 students, on Wednesday said students "got real passionate about wanting to wear their zip-up hoodies, but our intention is to make the school a safe environment, and part of that is to not wear outdoor-type coats to classes."

He said teachers had asked for clarification about the types of hoodies that are appropriate.

"I've learned a lot about fashion the past few weeks," Hartman said. "I'm proud of kids. They said this wasn't fair and they came and talked to me."

If a hoodie is like a sweater or flannel shirt in size and thickness, it's OK, even with a zipper, Hartman said. If it's thicker, quilted or oversized, then it's more like a zippered coat, and the students are still not allowed to wear coats to the classroom, he said.