Being a Doctor Who fan is a lot like belonging to a club. You’re part of a fandom that spans all over the world and crops up in the strangest of places. But as with all clubs, it’s not always a good idea to broadcast your love to everyone you meet.

So what are the signals we can use to sound out fellow fans without alerting n00bs and anti-Whovians as to our primary passion? What can we do that screams “I love Doctor Who” but only to other people who love Doctor Who?

Let’s have a look:

Clothes

Now, the entry level stuff is fairly obvious — the brown stripy suit, 3D specs and Converse combo, the frock coat, the fez, the long stripy scarf or the rainbow T-shirt — but there are more subtle clues you can send out into the world to try and find your fellow fans.

A cat brooch, for example, is just about the only fashion steal from the Sixth Doctor that won’t hurt the eyes of onlookers, and it’s subtle enough for non-Whovians to miss. Or any of the more modern Doctor jackets, starting with Eleven’s tweedy sports coat or Nine’s beaten up submarine captain leather.

If you’re feeling particularly flamboyant, how about a pocket watch (so you can pretend it’s got your Time Lord self hidden inside)? Or maybe a ruffled shirt, of the sort the Third Doctor would commonly wear? Or a thin black hoody with holes in. Most of the modern companions either wear variations on modern dress, or in Rory’s case, dress up like Romans, but maybe a gold star, like Adric’s, which could, to uninitiated onlookers, appear to be a sheriff’s badge.

Note: Don’t put question marks on your shirt collars. Only Doctor Who fans do that, and non-Doctor Who fans know this too. Secret and subtle is what we’re aiming for here.

Behavior

If you catch someone doing any of the following things, especially when it looks like they have no idea they are being watched, you can be sure they’re a Whovian and you can feel free to approach them to discuss your favorite TARDIS console:

• Playing with salt and pepper pots like they’re Daleks.

• Idly drawing tally marks on their arms.

• Walking past a graveyard and carefully looking several times at each of the statues.

• Putting on a red woolen hat to check the night sky, as if your granddaughter is somewhere out there.

Food

For the newer fan, there are the flashy and perhaps rather obvious delights of the fish finger and custard combo, or the packet of Jammie Dodgers or Custard Creams. But the hardcore Whovian has other ways to use food to alert fellow fans. The phrase “would you care for a jelly baby?” may once have been as ubiquitous as saying that bow ties are cool, but it’s been nearly fifty years since the Fourth Doctor started offering them to friends and foes alike, so it’s a decent place to start. Follow it up by holding a piece of celery to your lapel and you’ll definitely find out who your friends are.

You could also try taking a sip of wine and then immediately letting it fall back out of your mouth and into the glass, like Eleven does in “The Lodger,” and then claiming “I thought it would taste more like the gums.”

And for the real hardcore fans, there’s always this killer moment; when you’re having dinner, mime a saltshaker until someone gives you the salt, and then say “that’s too salty” (“The Unicorn and the Wasp”). If they reply “oh it’s TOO salty!” in a huff of exasperation, you know you have found your people.

Iconography

It’s one thing to have a TARDIS T-shirt or a toy sonic, and that would definitely reveal that you’re into Who. But would it actually attract hardcore Whovians? Possibly not.

However, should you have a any of the following secreted about your person in a tantalizing way, it’s a clue about your intentions that only the inner circle of fans will be able to identify:

A notebook with Time Lord circles (as seen at throughout of the Twelfth Doctor’s title sequence, amid all the cogs) or the Seal of Rassilon on the cover; a doodle of the 3W industries logo (also known as a Cyberman’s eye); a small circular pin depicting the UNIT logo or the Target books logo. A small tattoo of Clara’s leaf; phone wallpaper with the “It Takes You Away” frog; a desktop pen pot that is modeled on the Pandorica.

Music

It’s one thing to ostentatiously whistle Ron Grainer’s Doctor Who theme as you enter a room, but is that subtle? It is not. Far better to sort of hum the main refrains in Murray Gold’s “I Am the Doctor” as you go about your business.

Or if you really need to whistle, maybe Clara’s Theme would work better:

Total underground Whovian points go to anyone who can replicate the main melody to “Bill’s Theme” (unless it’s on a stripy recorder), and the same points go to any Whovian who spots it and recognizes it. That’s your musical secret handshake, right there.

Oh, and if you’re the type of person who still uses the ringtone on your phone — a rarity in this day and age — why not sample some of the classic synth-heavy soundtrack to “The Sea Devils”? Whovians will come running!

Expressions

If we’re seeking to subtly tip the wink to onlookers that we might be into Doctor Who without waving a sonic under their noses, we will need to use our quotes wisely. That means you can’t say “Rule number 1, the Doctor lies,” or even a hoary old stalwart like “reverse the polarity,” but there are a wealth of more subtle lines you can offer.

Pick one of these at an appropriate moment, let it fly and see what happens:

• “A footprint doesn’t look like a boot.”

• “Let’s go and poke it with a stick.”

• “Do what I do. Hold tight and pretend it’s a plan!”

• “Books! The best weapons in the world!”

• “You’ll find that it’s a very small universe when I’m angry with you.”

• “Never use force, you’ll just embarrass yourself. Unless you’re cross, in which case, always use force.”

• When revealing your surname: “Hopefully [it] means ‘noble valiant warrior’ and not ‘he who hits kittens with a hammer.’”

• “It is difficult to know what will be a waste of time until after the time has been wasted, by which time it is too late. So predicting what will be a waste of time is something of a waste of time. Unless it gives you pleasure, of course when it probably doesn’t count as a waste of time.”

• This particular thought, however often you may hear it, never seems to shrink in relevance: “The very powerful and the very stupid have one thing in common: they don’t alter their views to fit the facts; they alter the facts to fit their views.”

Note: Don’t unleash “hello Sweetie” unless you are already sure it will be received in the manner it is intended.

How do you plan to identify yourself to your fellow Whovians?