It was just a button, red around the outside, white in the middle, like a West German traffic sign. "Stop Strauss," it said, meaning Bavarian state Premier Franz Josef Strauss, who is running for federal chancellor this autumn against incumbent Helmut Schmidt.

Dagmar Henn, 16, pinned the button on her beret one day last December as she left for school. The school director asked her to take it off. Wearing political emblems, he said, is against school regulations.

When Dagmar's parents heard this, they were angry. Especially Dagmar's mother, who had been to America in the 1950s and remembered everyone there wearing buttons that said "I Like Ike." "That was what democracy was about, she said.

But in West Germany, freedom of political expression is still considered fragile. Although political currents run deep here -- and campaigns are waged in the etiquette of the bull ring -- the government persists in trying to keep potentially divisive views out of the classroom and work places of this already divided nation.

After Dagmar refused repeated requests by school authorities to stop displaying her button, the director suspended her. His superior, the Bavarian education minister, concurred. Now Dagmar's parents have taken the case to court.

No decision on political button-wearing has ever been handed down by the West German Constitutional Court. In a recent related episode, however, a labor court upheld the firing of a 19-year-old factory designer in Hemer for refusing to take off a compaign button while at work. The court called the button "a provocation" that "according to experience endangers the peace of the working place and disrupts the normal working process."

Such buttons -- along with bumper stickers, T-shirts and other assorted campaign paraphernalia -- are a relatively recent fashion in West German races. Since World War II, most West Germans have shown a reluctance to engage in open displays of political combat. A strong desire to keep the peace has often outweighed the exercised of free expression.

Rules differ somewhat from state to state and judgements have varied among local courts. But in most instances, activities of a political nature have been prohibited from school and office.

"There is a reason for these regulations," said Dieter Krywalski, director of Munich's Klenze Gymnasium, which Dagmar attends. "You must remember that the schools became political instruments during the Third Reich. Today, we believed school is not the place for political indoctrination."

Krywalski conceded that there is quite a gap between wearing a campaign button to turning the schools into a political arm of the state."On the one hand, it's just a trifle," he said. "But what if next week someone came in with a Nazi button or a Communist one? That would be a danger." He recalled the student radical movement of a decade ago and the threat that posed to peace in the classroom.

The school does offer a course in "political and social instruction," which officials say is intended to encourage students to form political opinions. But Dagmar's parents, in an interview, called the class meager and said it is nothing more than a textbook lesson in how the government works.

"They don't like to discuss, they administrate," said Klaus Henn of his daughter's school. As a lifelong civil servant, Henn has not been one to cause a political fuss. Nevertheless, he said this case has exposed a dangerous repressive attitude among some German authorities.

"They have a hard time drawing the line between free expression and agitation," he said. "Their have an abstract meaning of peace."

The mother, Christa Henn, a certified public accountant, said, "They are denying kids a chance to get used to their rights. They try to keep everything out.I was in America. It's a completely different way there. The kids get used to living with conflicts and they learn how to tolerate them. Here, all the things that would lead to conflict are prohibited."

As for Dagmar, she's made a new button which she wears to school. It looks just like the old one but in place of the words, "Stop Strauss," there is a picture of an ostrich, which in German is called a Strauss.

Dagmar's own picture has been in the newspapers. "When people pass now, they sometimes recognize me," she said."They say, 'Hey, that takes courage. I think it's bad to think it takes courage to wear a button."