Michael Keaton is one of many famous actors who have changed their name for professional reasons. Why does that SAG rule exist?

People assign labels to other people to help organize and personalize everyday life. Recent studies have even shown that they are not the only species on the planet that do so. Marmoset monkeys, bottlenose dolphins, and African elephants do the same. Things get hairy when the words are similar.

In Hollywood, the Screen Actors Guild (SAG) has long encouraged new members to avoid using the same name as a current member. The union, now SAG-AFTRA, even warns against using a similar term to gain clarity and product recognition and liability.

Because the membership list changes daily, SAG does not review it until a player is ready to join. During that process, another Professional Name Form is filled out, which asks for three possible stage names. When the start-up money is exhausted, the last name is considered.

Players can choose to ignore SAG warnings.

“While we strongly discourage members from choosing a job title that conflicts with a current member, SAG-AFTRA cannot prevent a member from using their legal name as their job title,” explained SAG-AFTRA spokeswoman Pamela Greenwalt. “If such a situation arises, SAG-AFTRA requires the applicant/member to sign a ‘Consent’ form in order for their application to be processed.”

Most members follow SAG’s advice—which makes sense. Players are essentially a branded product in human form, and a confused mind doesn’t buy it. As an entertainer, you want to be remembered.

Let’s take a look at some guidelines for names and actors who changed their monikers because of SAG favorites:

What is Michael Keaton’s name?

One name, one actor’s preference is not the only name rule in the organization. If an artist dies, his moniker is kept unassigned for three years from the date of his passing. If a current member changes their name, the old one remains unassigned for three years. If a member is expelled from the union, his name is immediately available. If a member honorably withdraws or defaults on membership, their name is retained for five years.

SAG’s rules about naming have recently come to light because Beetlejuice juice star Michael Keaton.

Keaton was born Michael Douglas on September 5, 1951. He grew up the youngest of seven in a suburb of Pittsburgh. When he tried acting in the 1970s, there were two other competitors. There was Kirk Douglas’ son Michael Douglas and a talk show host named Mike Douglas. A quick look in the phone book inspired his new last name, Keaton, which seemed to work well for the man.

Keaton’s breakout role came in a 1979 CBS sitcom Working Stiffs. He would strengthen his stand as a comedian in films like this Night Shift again Mr. Mother and earn a star with Beetle juice again Batman.

These days, Keaton is changing his name again. He wants to be known as Michael Keaton Douglas from now on, as recently reported by People magazine, a mixture of his stage and real words. We can honestly say that the public knows who he is now and he is stable enough to avoid confusion.

Julianne Moore

Julianne Moore also had to use a stage name when she joined a union (in this case, Actors’ Equity, the stage actors’ union) and she wasn’t too happy about it. She was born Julie Anne Smith. He looked to the mentors of other family members for inspiration.

“My father’s middle name is Moore; mother’s name is Anne. So I just beat Anne to Julie,” he explained New York Times in 2001. “That way I could use both of their names and not hurt anyone. . . But it is bad to change your name. I was Julie Smith all my life, and I didn’t want to change.

Emma Stone

Emily Jean Stone also found herself in this situation when she was 16 years old, as she explained W magazine. He first tried the name Riley, but he kept forgetting to respond to it on set. Finally he got to Emma because it sounded like Emily. He told W that his good friends used to call him M anyway, it worked.

Diane Keaton

No, Diane and Michael are not related. Both are simply victims of SAG policy. Diane’s real legal last name is Hall, like her iconic character in the movie Annie Hall. He changed it when he joined the union.

Michael J. Fox

Michael kept most of his real name but had to add a letter. (As his foundation explains, there was already a “Michael Fox” at SAG.) His given name is Michael Andrew, Fox but he chose to go by Michael J. Fox professionally to honor actor Michael J. Pollard.