O2 customers suspected of illegally sharing pornographic films made by Ben Dover Productions will begin receiving letters from the film-maker shortly.
The firm won a court order in March forcing O2 to pass on details of the owners of 9,124 IP addresses linked to illegal downloads.
The High Court has now approved the text of the message that will be sent.
Ben Dover has said its focus is on users who had uploaded films to others.
The commercial director of the firm - which is registered at Companies House as Golden Eye International - said that parties who "simply downloaded one film" would not be pursued.
"In our first letter we seek to find out more information regarding evidence of an infringement of our copyright," said Julian Becker.
"Depending on the response to our letters we will then decide our next action."
It is understood that recipients will be told what to do to negotiate a settlement, and will be warned that if they do not respond they could be found liable.
They will be given 28 days to reply after the judge said that a 14 day limit requested by Ben Dover was "unreasonable".
The firm was also told it could not specify compensation of £700 but should individually negotiate a settlement sum with each defendant.
The judge added that a threat to tell users it would ask the ISP to "slow down or terminate your internet connection" if they did not comply was unjustified.
A statement from O2 said: "We are pleased that the court has taken a robust approach and controlled the tone and content of the letter Golden Eye proposes to send to our customers. We are also pleased that the judge acknowledged the unique position we are in, and agreed that we have approached this issue in a reasonable way."
The action is the latest in a series of efforts to clamp down on online piracy.
US authorities shut down file-sharing site Megaupload in January and are attempting to extradite its founder and administrators from New Zealand to stand trial for copyright infringement and other related offences.
Courts in the UK, Greece, the Netherlands, Italy and India have also ordered ISPs to block access to a number of file-sharing sites over the past month.
While such efforts form an attempt to clamp down on a wide range of media piracy, Ben Dover suggests its sector of the industry has been particularly hard hit.
"Due to the nature of the way most consumers view adult content, the adult business has been affected far worse than mainstream film due to the fact that the pirates cannot replicate the cinematic experience of mainstream films," Mr Becker said.
"Our core business has been decimated by piracy and we are pursuing several projects in combating both the internet sites that facilitate online piracy as well as the end violators and the physical DVD pirates."
Campaign group Consumer Focus had previously attacked Ben Dover's claim for £700 compensation as "unsupportable", and said it now welcomed the fact that the sum would not be mentioned.
"'We do not condone copyright infringement, but neither do we want to see any innocent people pursued for something they are not guilty of, or intimidated into paying out large sums of money to make the intimidation go away," said the group's chief executive Mike O'Connor.
"The court has recognised that bill-payers should not be automatically assumed to be guilty for alleged copyright infringement on their internet connection, and that firms should not send threatening letters as Golden Eye originally intended to do.
"It is welcome that the court is putting further requirements on the letters that are sent out. These will need to provide consumers with appropriate protection from unjustified intimidation and take full account of customers' rights."