New York City Schools Chancellor Carmen Fariña released on Friday a long-awaited update to the public school system's discipline code that would make it harder to remove a student from school for minor infractions, following years of complaints by the New York Civil Liberties Union and other groups about the overuse of suspensions.

The proposed revision, subject of a March 2 hearing, would bar principals from suspending a student just for cursing or wearing the wrong clothing. They could still suspend for other types of insubordination, but only after obtaining approval from the Office of Safety and Youth Development.

"What that will do is make a sense of uniformity," said Vincent Schiraldi, senior advisor to the Mayor's Office of Criminal Justice. "So you don't get one kind of treatment in one school and an entirely different kind of treatment in another school for exactly the same behavior."

The code would also make it much harder for schools to use physical restraints on students under the age of 12.

“This is a critical step forward for our schools and our students,” Chancellor Fariña said in a statement. “Today’s changes will protect students from bullying and violence, and provide relief and a better school experience for students who need to be focused on their learning and not constantly worry about getting suspended for any minor incident.”

More than 50,000 students were suspended during the last school year. That was about the same as the previous year, but officials noted a slight decrease after January, when the new mayor took office. The de Blasio administration said it's also seeking to end the disproportionate punishments of African-American and special-education students, who are are four times more likely to be suspended than their peers.

The updated discipline code emphasizes the use of what's known as restorative justice, an approach that resolves conflicts in a holistic manner and tries to repair the harm in the context of the community where it occurred. The goal is to get students can take responsibility for their mistakes and work on not repeating it. The Department of Education has allocated $1.2 million for training staff in restorative practices at 100 schools by September.

David O'Hara, principal of Expeditionary Learning School for Community Leaders in Brooklyn, said he was glad to see the city put a big effort behind restorative justice practices. He's been using them in his high school and said overall discipline incidents have decreased by 46 percent this year.

"In a retributive system, the one who causes harm must suffer equal harm to re-balance the social scale," he said. "In a restorative system, the goal is to repair harm and reconcile the community."

The announcement was met with praise from civil liberties and child advocacy groups. The New York Police Department which employs and trains school safety agents also praised the proposed changes, and promised to increase training for the agents.

However, advocates in the Dignity in Schools Campaign said it didn't go far enough to end suspensions for insubordination, which make up the largest category of removals.

“When we suspend kids, we are only making the problem worse, and pushing them further into the school-to-prison-pipeline," said Nicole Riley, a member of the group who teaches at Edward A. Reynolds West Side High School. She called for more support services and interventions.

Bernard Dufresne, a staff attorney with Advocates for Children of New York, said he also hoped to eventually eliminate suspensions for insubordination. However, he called the proposed new code a "good start." He also noted the appointment of a new School Climate Leadership Team that will be reviewing data and advising the administration on additional changes.

Nelson Mar, a staff attorney at Legal Services NYC in the Bronx, said he was honored to be part of the effort.

"For too long New York City has treated school discipline as an extension of the criminal justice system," he said.

Changes to the discipline code were expected since last summer, but officials said the administration wanted to consider the input of parents, students, teachers and police. It includes a pilot program in the Bronx with the NYPD that will replace summonses for student misconduct with warning cards. It also continues to expand training for school safety agents in crisis intervention.

The city already agreed to deter schools from calling 911 for student with behavioral problems.