Wireless Festival will remain in Finsbury Park but artists have been warned not to swear or play “vulgar, obscene or banned songs”.
Acts could even have their volume turned down if they are too loud at the event in London.
They have also been cautioned about wearing clothes that could offend the public, such as anything exposing their private parts.
The new rules were laid down for the event’s promoter, Live Nation, following a review after complaints around noise, security and drug-taking at the festival.
Haringey Council granted a licence for the next festival but imposed new conditions.
One was that performers should “not sing or play any vulgar, obscene or banned songs or carry out indecent acts or make any vulgar gestures, actions or remarks during the performance, or at any point whilst using an amplification device, including the use of expletives”.
Acts should also avoid attire that could “offend the general public, e.g. attire which exposes the groin, private parts, buttock or female breast(s)”.
Sound levels will be monitored and a sound engineer must “take remedial action” to reduce the volume if the limits are exceeded or “on receipt of substantiated complaints of public nuisance”.
The festival will also end at 9.30pm on the Sunday night, 30 minutes earlier than before, with the last sale of alcohol now at 9pm instead of 9.30pm.
Councillor Kirsten Hearn, Haringey’s Cabinet Member for Environment, said: “Wireless Festival is a world class urban event that helps to fund the park the whole year round and makes a major cultural contribution to Haringey.
“We’re a diverse borough and many of our residents, as well as people from across London, attend and enjoy the festival – it is a celebration of some of the world’s biggest music acts.
“Residents in Haringey and our neighbouring boroughs – as well as Islington and Hackney councils – have been clear about the improvements they want to see and I want them to know that the council has heard their concerns.
“We will work to address these with residents and partners at Finsbury Park.”
Friends Of Finsbury Park, a group that had complained about the event, said it was pleased with some of the new conditions but would still like to see the attendance reduced.
It also suggested it may appeal against the decision.
A message on its website said: “We are pleased that the committee has taken into consideration the testimony of our witnesses and noise expert on the excessive and invasive noise that is produced by the festival and agreed with the Friends’ case that loud music from Wireless, including bass level noise, has caused a public nuisance.
“We therefore welcome the decision of the committee to incorporate our proposed noise limits and noise monitoring conditions.
“We are also pleased that the event will finish earlier on a Sunday, as we had suggested.
“However, several of our proposed licensing conditions have been disregarded by the committee, of which the most important is our request to reduce the number of attendees at the event.
“Even with improved management of the festival, it is simply not possible to reduce the excessive level of public nuisance caused by a festival and the impact it has on the park without reducing the number of attendees below the current limit of 50,000.”
The message said Live Nation and the Friends Of Finsbury Park have until November 12 to appeal against the licensing decision.
“Therefore we will spend the coming days looking through the report of the committee in further detail before coming to a decision on what next steps would be best to protect the interests of the community,” Friends of Finsbury Park said.