At some Montgomery County high schools, students can't wear hats. At others, backpacks are not allowed. And now, according to a directive issued last week, students at all 23 high schools will have to wear photo IDs this year.

It's back to school for the post-Columbine security-conscious.

"Military installations that protect high-power secrets have badges. We're just trying to protect students," said Dan Shea, principal at Quince Orchard, where students already have badges, they just don't wear them yet. "We have precious cargo here."

The directive, which caught some principals by surprise, comes after an audit found internal security lacking at Montgomery County schools. The audit, by the National Alliance for Safe Schools, strongly recommended that all students wear photo badges to better delineate those who belong inside the building from outsiders.

"I don't think the kids will like it at first; even my own daughter's not thrilled," said school board member Nancy J. King (Upcounty). "But, like anything, they'll get used to it. We want teachers and students to focus on learning and not worry about being afraid."

King, who along with all other nonschool staff will be wearing a photo ID by November, said the board will watch how badges work at the high schools and may consider requiring all middle school students to wear them next year.

The news about the ID badges came as new School Superintendent Jerry Weast, County Executive Douglas M. Duncan (D) and Police Chief Charles A. Moose outlined new security measures for all Montgomery County schools, including crisis response plans that require schools to stock flashlights, batteries and cell phones. Officials also announced a new program to give each school a uniformed police officer "liaison." Some schools in the District and Prince George's County require students to wear ID badges as well.

High school principals, many of whom are scrambling just to get schools opened tomorrow, have until February to enforce the new policy. Some welcome the change as an easier way to get to know each student by name.

But many wonder how they can get students to comply. "Enforcement of this is going to be a bear, a real bear," said Seneca Valley High School Principal Wayne Whigham.

Richard Towers, principal at Einstein High School, held focus groups with students last year on photo IDs. "They said, unless these are things we need to use on a daily basis, they won't wear them," he said. So he is considering putting a bar code on the badges and using them to let students check out library cards, pay for lunch or get into athletic events.

That's how the cards worked last year at Montgomery Blair, where, at the request of parents, the 2,700 students wore ID badges last year.

After a spotty record first semester, when rebellious seniors refused to wear them, Principal Phil Gainous cracked down.

"We said, if you don't have your badge, you can't go to class, you can't go to the library, you don't exist. Go sit in the cafeteria," Gainous said. "By the second week, 98 percent of the kids were wearing them."

The get-tough policy set off waves of protest, as students who forgot their badges and were sent to the cafeteria were given unexcused absences from their classes. Gainous modified the policy, requiring students--and staff--who lost or forgot their badges to report to security and pay $5 for a replacement.

Richard Montgomery Principal Mark Kelsch bought a special ID-making machine last year for the 1,200 10th-, 11th- and 12th-graders who leave the campus for lunch. He plans to expand that system to meet the county mandate. Twelve other schools already have contracted with their yearbook photo company to have IDs made when yearbook pictures are taken.

Gainous said: "My sister works for IBM and she can't even go to the bathroom without touching a pad that recognizes her handprint. That's the real world now. Schools are just part of that."