It refers to a person without naming it. It is a synonym of cited, referred to, named, indicated, above, mentioned, alluded.
Sometimes you can use impersonal way. In class, e.g... when read some rules... said " Students arriving five minutes late may not come into the classroom ". The above will remain in the library. Somehow replaces the names, a group or a person... not a pronoun would be but it seems it.
Person that you don't want to mention its name due to certain reasons such as anger, among others.