The joke originated when John Spaeth posted a false notice for a Carberry lecture on a bulletin board at Brown in 1929. The lecture, on "Archaic Greek Architectural Revetments in Connection with Ionian Philosophy" was, of course, never given, and when asked, John Spaeth obligingly provided false details about the professor's (fictional) family and (non-existent) academic interests. The joke has been embraced since that time, at least at Brown, and Carberry has traditionally been scheduled to lecture every Friday the 13th and February 29th (he of course "misses" all of them), and a general mythology has grown around him and his family. Students have taken great delight in inserting references to him in otherwise serious journals, as any such reference which fails to point out his non-existence seriously undercuts the reputation of those works.
Those "in" on the joke, however, also enjoy the use of his name: a snack bar on campus and the library's card catalog are named for him.
In 1991, Carberry was awarded an IgNobel Prize for interdisciplinary work, making him one of only three fictional people to have won the award.