Doctor Who is a franchise perfect for the detail-oriented: Full of in-series rules, long-running inside jokes, and a history that goes back more than 50 years, it's the kind of show that's tailor-made for fans to obsess over. If you want to beef up your "Doctor Who" geek cred, or just want to know how to avoid irritating the show's most avid fans, here are the six things that bug Whovians the most.

1. Expecting Perfect Continuity

Time travel is a tricky topic. With paradoxes built into the concept, writing a show where the logic tracks all the time is nearly impossible. With "Doctor Who," this is especially difficult, given the show's 50-year history and constant revising. All of which is to say: Expecting a single, infallible canonical story line isn't really reasonable with "Doctor Who," and to a degree, enjoying the show means going along with a certain amount of contradictions -- what the Doctor himself calls "wibbly-wobbly, timey-wimey" logic. Each episode follows the same general rules ... until it doesn't, and that's half the fun. In contrast, spending time asking questions that ultimately don't matter in the long run -- like, "So which is it, is the doctor hundreds of years old, or thousands?" -- can take the fun out of the whole experience. Your best bet: Don't sweat the small inconsistencies.

2. Watching 'Torchwood' First

"Torchwood," itself a strong sci-fi franchise with legions of fans, is actually a spinoff of "Doctor Who" -- the former's title being an anagram of the latter's. "Torchwood" is a "Men in Black"-style show about a secret agency charged with protecting London from alien threats. And while the show can be enjoyed as a standalone entity, it borrows heavily from the "Doctor Who" mythology, to the point that it's far more enjoyable after you've watched at least some of the Doctor's adventures. In addition to a few outstanding crossover episodes, "Torchwood" borrows villains, protagonists, and at one point, the Doctor's detached hand, as critical plot points -- making "Doctor Who" practically required viewing for hardcore fans.

3. Calling the Doctor 'Doctor Who'

Despite the title, the hero of the show is known as "the Doctor." While some fans are quick to point out that the credits of the first few seasons in the 1960s listed the character's name as "Doctor Who," on-screen, he only goes by "the Doctor," and thus calling him "Doctor Who" is inaccurate. Within the show, it's become a bit of a running joke. When he introduces himself to someone new, saying, "I'm the Doctor," they frequently respond with "Doctor who?", to which he responds, "Quite right."

What's more, the show frequently mentions that the Doctor has a real name that he's kept a secret, and it cannot be pronounced by humans. Just like the Doctor himself, debates about what to call him and the etymology of his name will likely last for centuries, but one thing's for sure: Calling him Doctor Who isn't correct.

4. Comparing 'Doctor Who' to 'Star Wars' or 'Star Trek'

Not all science fiction is the same, and fans take the differences very, very seriously. Because the stories in "Doctor Who" happen across space and time, their scope is far broader than the space colonization of "Star Trek" or the galactic Jedi-opera of "Star Wars." An episode of "Doctor Who" is just as likely to take place in 16th-century England as it is on another planet in the future, thus giving it a much bigger palate of colors to paint from than the straightforward contexts of "Star Wars" or "Star Trek." And while it's pretty likely that all three franchises have a lot of fan overlap -- let's face it, they're all terrific in their own ways -- fans are quick to remind the uninitiated that "Doctor Who" is truly unique in its ability to take place in any time period.

5. Forgetting About the First 40 Years of the Franchise

"Doctor Who" first premiered on TV in 1963, and has been on and off the air ever since. The show's biggest gap was from 1996 to 2005, at which point producer Russell T. Davies regenerated it into its current incarnation (commonly known as "NuWho" by fans). While "NuWho" isn't a reboot, it certainly represents the modernization of "Doctor Who." For younger fans, it's the only version of the franchise they know. Nonetheless, longtime fans frequently bristle when they encounter others dismissing or forgetting about everything the first eight iterations of the Doctor went through in episodes prior to 2005. Fans who start with the 2005 series are still getting the cream of the crop when it comes to "Doctor Who," but nonetheless, the experience is that much richer for those familiar with the first 40 years of the franchise -- not to mention, it gives them a leg up in any Doctor Who-related trivia game.

6. Calling the TARDIS a Phone Booth

The Doctor's ship for traveling through time and space -- "Time And Relative Dimension In Space," or TARDIS -- is a vessel he stole from his own people, the Time Lords. Originally, the Doctor disguised the stolen property as a police call box, and, according to his not-exactly-consistent version of events, the chameleon circuit broke, making the disguise permanent. Those not in the know commonly refer to the TARDIS as a phone booth, which is incorrect on multiple levels, as it's a spaceship, and British phone booths are typically red and not blue. If you're looking to impress a "Doctor Who" fan, make sure you mention the TARDIS's defining feature: It's bigger on the inside.