Have you recently seen a wedding photo on Instagram with a flood of comments calling the couple an "OTP?" Here's what this acronym means---and how to use it when a pairing makes you swoon.

One True Pairing

OTP is an initialism that stands for "one true pair" or "one true pairing." It refers to a specific coupling between two fictional characters that a person or group is deeply fond of. If someone enjoys the relationship between Princess Leia and Han Solo from Star Wars, they might say, "Han Solo and Princess Leia are my OTP." This signals to other fans of the pairing that they support this relationship.

The acronym shares many similarities with "ship," short for "relationship," which is another term that refers to pairings between fictional characters. People can use it for any pair of characters that people feel work well together, even if they're not necessarily together in the actual work. For example, someone might adamantly say, "Harry Potter and Hermione Granger is my OTP," even if these two characters are not romantically involved in the books.

Alternative definitions for OTP include "on the phone," which is used in informal contexts to explain to someone why you were recently unavailable to talk. It's very similar to the slang term AFK, or "away from keyboard." It can also mean a "one-time password," a measure used to secure login sessions and online transactions. We'll discuss one-time passwords in greater depth later.

A History of OTP

OTP emerged in fan websites during the late 1990s and early 2000s. It became especially prominent when fan communities began to form around big fictional properties, such as Supernatural and Harry Potter. The first definition for OTP on the internet slang repository Urban Dictionary dates to September 2003. It reads, "one true pairing, used in fandoms to express what characters you ship," and provides an example from the TV show The West Wing.

As fan communities began to grow, the use of OTP became more widespread. One significant factor was the emergence of fan fiction works, which are unauthorized fan-written stories based on an existing fictional property---some fan fiction stories revolved around a user's "OTP" or one true pairing.

Since then, the use of OTP has spread outside of fan communities. It's not uncommon to see OTP being used on social media by fans of a particular celebrity couple. You might even see the acronym pop-up in the comments of your friend's engagement announcement on Instagram. People broadly use it to refer to a couple they believe is an excellent example of a healthy relationship.

My OTP and Your OTP

The subject of "what is the real OTP" can be a source of animosity among fans of the same franchise. There are many franchises where romantic relationships are contentious and frequently change. That inspires fans to latch onto particular pairings and argue with others on the internet about which OTP is the best one.

If you browse for long enough on the internet, you might encounter some strange OTPs. You'll find people pairing characters who have nothing to do with each other or are outright enemies. You might even find pairings of characters from completely different franchises. For example, someone's OTP might be Ross from Friends and Hermione Granger from Harry Potter.

You can also use "OTP" in a joking way to refer to things that you believe make a great pair. For example, you might say, "football and drinking beer is my OTP," if you think that these two activities are perfect together.

One-Time Passwords

Another common definition of OTP is "one-time password." This is a password or authentication code that is valid for a single session or use case. These codes are often used to complete a two-factor authentication login or complete a sensitive transaction, such as a credit card purchase.

Related: Here's Why You Should Use Two-Factor Authentication (2FA)

One-time passwords are typically sent via a direct message to you or with an authenticator app. You might also see these codes referred to as an OTAC or a one-time authorization code. If your banking app or encrypted messaging service asks you for an OTP, they're probably not asking about your favorite pairing!

How to Use OTP

Before you start calling everything your OTP, don't forget that this is a very informal acronym. When used in professional contexts, it can easily be confused for a "one-time password," so be careful.

Here are a few examples of OTP in action:

• "My OTP is definitely Aladdin and Jasmine."
• "What is your OTP in the Transformers franchise?"
• "Jessica and Eric are my OTP."
• "You know what my OTP is? Steak and eggs."

Did you enjoy learning about OTP? Then you should check out our pieces on other internet slang terms like ELI5, TIL, and TTYL. You'll be an internet-speak expert in no time at all.

Related: What Does "TTYL" Mean, and How Do You Use It?