Heat magazine's Lucie Cave told the Leveson Inquiry into press standards it would be a "very useful tool" if celebrities kept a body like the Press Complaints Commission (PCC) updated on their circumstances.
But OK! editor Lisa Byrne warned that such a register could place limits on the reporting of stories about well-known people.
"Every celebrity might say, 'no, I don't want any pictures of my family ever again'. Then it could cause a problem," she said.
Inquiry chairman Lord Justice Leveson questioned Ms Cave, Ms Byrne and Hello! co-editor Rosie Nixon about the idea of a list of which celebrities did not want to be featured in the media.
"Would it be of value if there was a register so people likely to be of interest to your magazines or indeed the wider press could say, 'I'm very sorry, I want to be private'?" he asked.
"Would you be assisted by some mechanism that clarified all that?"
Ms Nixon replied: "Yes, I think we would."
Ms Cave added: "It depends on the circumstances of the celebrity at the time. It might be there's a moment in their life where they particularly don't want a photograph taken of them for whatever reason.
"But then at other times they might be happy to have a photograph taken... It would be a very useful tool for us if they used a body like the PCC to update them on their circumstances."
The hearing was told there is a "bounty" on the head of celebrities' newborn babies because paparazzi can make a lot of money if they get the first picture of the child.
Singer Charlotte Church told the inquiry in November that she signed an exclusive deal for a magazine article when her first baby was born to "take away the value" of paparazzi pictures.
"My decision was based upon the fact that photographs of my children would have been taken anyway, with or without my consent, and this was the lesser of two evils," she said.
Ms Nixon said today: "The sad truth is that there is almost a bounty on the head of that child for the first photos. They can make a paparazzo a lot of money."
The Hello! and Heat editors said they took their magazines' membership of the PCC very seriously.
Ms Nixon said: "Our website adheres to the PCC code, as does the magazine. Our web editor sometimes jokes that we're often the last website to put up news stories because we are checking out the background to them."
Ms Cave said: "The PCC embodies the ethics by which we work so it's of prime importance to us, and it's something that is just entrenched in the people that work at the magazine anyway."
Ms Byrne said OK!, which is part of Richard Desmond's media empire, was not part of the PCC but it still adhered to the body's code of practice.
The inquiry heard that stories pre-agreed with celebrities make up about 70% of Hello!'s content and 80% of OK!'s, and that both magazines will give copy approval in some cases.
Ms Nixon said certain stories could provide a big increase in sales, giving the example of the issue devoted to last year's royal wedding, which sold more than one million copies in just a few days.
Ms Cave said Heat was one of the only magazines that will point out when paparazzi photographs appear to be set up with the co-operation of the celebrities they feature.
The discussion of magazine spreads of the weddings, babies and homes of the rich and famous took a lighter tone than some of the inquiry's previous hearings.
Directed to a Heat photoshoot of celebrity chef Heston Blumenthal dressed as an egg, Lord Justice Leveson wryly observed: "It's a very different sort of journal to my normal, but fair enough."
Foreign titles were likely to take a softer line on publishing pictures of certain famous figures, the inquiry heard.
Ms Nixon said: "We've noticed foreign magazines are able to publish photos of the Duchess of Cambridge that we wouldn't publish here."
These included images of Kate going about her daily life when she was not at an official event, she added.
Ms Cave justified photos in the latest issue of Heat showing Simon Cowell on board a yacht with a young woman on the grounds that the music mogul "enjoys the lifestyle that goes with his celebrity".
"We took the decision that he's clearly playing up to the paparazzi that are there so, in this instance, we didn't feel he would have a problem with us printing this picture," she said.
But she admitted that staff at the magazine were "mortified" by the "grave mistake" it made in printing a sticker insulting the disabled son of glamour model Katie Price.
Heat apologised for the 2007 incident.
Ms Byrne denied that OK! misled readers with some of its front pages which, it was suggested, occasionally promised more than they delivered.
A headline about the wedding of footballer Wayne Rooney and his wife Coleen was cited as an example.
"I can understand someone might buy it thinking 'Oh, that's the start of the wedding of Wayne and Coleen'," Ms Byrne said. "But anyone who knows the magazine knows that if we had the wedding of Wayne and Coleen, it would be a full image and nothing else on the cover."
She also defended a recent headline about the Duchess of Cambridge's 30th birthday, which referred to "the intimate party, gifts, star guests and delicious menu".
She told the hearing: "We had spoken to the Palace, who told us it was going to be a very quiet occasion and really intimate between William and Catherine...
"The rest was speculation (based on) what gifts they had bought in the past, their favourite food."
She pointed out that the magazine had not added the word "exclusive" anywhere on the story.
Prime Minister David Cameron set up the Leveson Inquiry last July in response to claims that the News of the World commissioned a private detective to hack murdered schoolgirl Milly Dowler's phone after she disappeared in 2002.
The first part of the inquiry, sitting at the Royal Courts of Justice in London, is looking at the culture, practices and ethics of the press in general and is due to produce a report by September.
The second part, examining the extent of unlawful activities by journalists, will not begin until detectives have completed their investigation into alleged phone hacking and corrupt payments to police, and any prosecutions have been concluded.
The inquiry was adjourned until Monday.
PA
