St. Elsewhere (spoiler!) ended with the reveal that the entire series happened inside the imagination of Tommy Westphall, an autistic child in the series. Homicide featured an episode in which one of the doctors on St. Elsewhere was investigated. Thus, both shows share a continuity, and, since St. Elsewhere was a figment of Westphall’s imagination, so must be Homicide. Turns out that 278 other shows cross over with Homicide.
Very neat, but I do have some qualms with their methodology. They include a show, with some exceptions, whenever a character or event crosses over with another show, or when a character, event, or item from a show is mentioned within another show. The first is a given. The second, I’m not so sure.
Direct character crossovers certainly apply and confer status that two shows exist within the same multiverse. All the events of Friends coexist with the events of Joey, as do those of Mad About You, via sisters Phoebe and Ursula.
All of the Star Trek series feature character crossovers, but I don’t buy this connection: “John Larroquette Show referenced Yoyodyne. Many years in the future the same Yoyodyne built starships for Starfleet in the 24th century, including the U.S.S. Brattain and the U.S.S. Phoenix on Star Trek: The Next Generation, which features the adventures of the crew of the U.S.S. Enterprise-D.” They also use Yoyodyne to connect to the Buffyverse. Must it be the same Yoyodyne? It’s not just a funny name that happened to be in all the series?
Often TV shows are produced by the same companies (as with Star Trek), and little easter eggs pop in. An example: “Charlie from Lost was in a band named Driveshaft. Alias Sydney threw a party and the music playing at the party was Driveshaft song.” Is the existence of Driveshaft’s We All Everybody on Alias enough to say that both exist in the same continuity? Probably. How about this one: “In the Jan 25th episode of Veronica Mars Veronica’s fortune contained the numbers that won Hurley from Lost the lottery.” Here I’d have to say no. The numbers are important to Lost, and their appearance all over the place on that show is a plot point, but their appearance on Veronica Mars is an homage. Inside Veronica Mars’s continuity, those numbers would just be numbers. (Battlestar Galactica, however, is explicitly reference as a work of fiction in episodes of Veronica Mars and The Office (USA).)
“Charlie of Lost once dated a girl whose father worked for a paper factory in Slough. The paper factory in Slough is the paper factory of The Office (UK).” (My memory is that Hurley also owns this company, and I think Locke worked there.) Does the mention of a paper factory in Slough necessitate that the factory is The Office’s Wernham Hogg? Again, I’d say no. It’s a coincidence, but it’s not enough for me. The Office was a BBC documentary within its own universe. If we saw characters of another show watching it, I think we could say that they share a universe, or even if we saw its logo somewhere on some stationary, but just mentioning the factory doesn’t cut it. I think a concrete crossover (a character, a direct reference to an event, a recognizable physical item) is enough to justify a link, but an homage or some sort of reference which would be mere coincidence inside the diagesis isn’t.
Now here’s a very good one: “On a balloon capsule on Lost all of its sponsors are listed and among them is Nozz-a-la Cola. Nozz-a-la Cola is a fictional product created by Stephen King & mentioned and consumed in Kingdom Hospital.” Even better, though the writers of this page don’t seem to know it, is that Nozz-a-la Cola appears in The Dark Tower, which establishes that all of Stephen King’s books are connected, and establishes its own multiverse containing “a billion” other worlds. Stephen King himself appears in the story as the author of itself. This being true, it means that not only did Tommy Westphall imagine the world of St. Elsewhere and those of all the other shows connected to is, but also Stephen King the author, all of his books, and their sprawling multiverse which all spin around The Dark Tower. And all things follow ka.