Real Person Fic, or RPF, is fanfiction exclusively or largely about one or more famous people, often actors or band members, though no public figure is safe. RPF is banned by most websites that host fanfic, including the Pit. It can still be found on the websites, usually, in the case of actors, under the category for whatever movie they were in.
A common kind of RPF is about the actors who are in a movie together and often involves them falling in love, especially if their characters do the same (or the typist thinks that they should have). There are also some that involve an actor meeting the character that they play. Slash of this type is abbreviated to "RPS" for Real Person Slash.
Real People, Fanfiction, and the PPC
RPF is usually abhorred by PPCers for being offensively presumptuous at best and exceedingly creepy at worst. However, please note that while missions to RPFs were done in the past, we no longer allow it. If it's offensive for fic writers to presume to know the inner thoughts and private lives of living people, it's offensive for us to presume we know better.
However, not all fanfiction including real people is considered RPF. If the story is exclusively or in large part about a real person, it's probably RPF, but if they're only a minor or incidental character, it may not be. Other factors also make a difference: writing about the documented public-facing character of a famous person is less problematic than writing wild speculation about their private life, and writing about long-dead historical figures is less (or at least differently) problematic than writing about the living or recently deceased. As always in matters that may be sensitive, PPC writers are expected to exercise discretion, good taste, and respect for the real person's family and/or those whose lives they have affected for good or ill.
In-universe, real people encountered in fanfiction by agents should be treated like canon characters whose home continuum is World One (the "Real World"). They will probably need to be neuralyzed and sent back there.
Missions to Real Person Fic
Historical missions to Real Person Fic can be found under their home continuum, the Real World. Again, please note that we no longer do this.