An R13 offence includes insulting, abusive language, and/or gestures against a match official.
Ranui Swanson got their final warning on May 2 for breaching the code of conduct. At the time they were warned they would be withdrawn from all NFF competitions immediately and would not be guaranteed immediate entry next year.
But the short-lived ban was lifted last week after assurance from the club's committee that it would continue to monitor matches and behaviour closely. The players and coaches had also given their assurance that they would respect referees' decisions and abide by the laws of the game.
"As a result NFF is satisfied that the Ranui Swanson Club committee has taken our concerns seriously, have acted swiftly to address immediate concerns and has put in place processes not only to help prevent incidents but also to manage them in the even that they should occur," the NFF statement said.
Ranui Swanson FC president Tracy Smith said they would be making no comment about their reinstatement to the 2019 season, or the steps they had taken to address the misconduct issues.
But a player in a competing team in the Northern Football Federation has expressed concerns over Ranui Swanson being let back into the competition and said it didn't send a strong message to players.
The player, who did not want to be named, said football bosses needed to take a stronger stance. He feared there would be an increase in the bad behaviour and abuse to referees if federations didn't crack down hard enough.
"What needs to happen to get banned ... physical abuse of a ref? Come on football federations, make a stand," the player said.
Football and rugby officials have been cracking down on abuse on referees after a number of attacks in the past year.