Starting next month, city police will hand out information cards to people they stop, question and frisk but don't arrest.
The measure begins September 21.
Officers must check boxes on the cards explaining why a stop was made, with reasons like suspicion of weapons possession or drug dealing.
The cards will also give the officer's name, rank and shield number.
Patrolmen's Benevolent Association president Pat Lynch released a statement criticizing the initiative.
"They are just one more item on the ever-growing list of anti-public-safety measures that will put an end to proactive policing in this city and ultimately accelerate the increase in crime and disorder that we are already seeing in our public spaces," he said.
This mandate is one of the reforms recommended by the NYPD's federal monitor, and was approved by a federal judge.