Shipping (derived from the word relationship) is the desire by followers of a fandom for two or more people, either real-life people or fictional characters (in film, literature, television series, etc.), to be in a romantic or sexual relationship. Shipping often takes the form of unofficial creative works, including fanfiction and fan art.
Etymology
The usage of the term "ship" in its relationship sense appears to have been originated around 1995 by Internet fans of the TV show The X-Files, who believed that the two main characters, Fox Mulder and Dana Scully, should be engaged in a romantic relationship. They called themselves "relationshippers" at first; then "R'shipper", and finally just "shipper".
The oldest recorded uses of the noun ship and the noun shipper, according to the Oxford English Dictionary, date back to 1996 postings on the Usenet group alt.tv.x-files; shipping is first attested slightly later, in 1997 and the verb to ship in 1998.
Notation and terminology
"Ship" and its derivatives in this context have since come to be in widespread usage. "Shipping" refers to the phenomenon; a "ship" is the concept of a fictional couple; to "ship" a couple means to have an affinity for it in one way or another; a "shipper" or a "fangirl/boy" is somebody significantly involved with such an affinity; and a "shipping war" is when two ships contradict each other, causing fans of each ship to argue. A ship that a particular fan prefers over all others is called an OTP, which stands for one true pairing.
When discussing shipping, a ship that has been confirmed by its series is called a canon ship or sailed ship, whereas a sunk ship is a ship that has been proven unable to exist in canon, or in other words, will never be real nor confirmed.
Naming conventions
Various naming conventions have developed in different online communities to refer to shipped couples, likely due to the ambiguity and cumbersomeness of the "Character 1 and Character 2" format.
The first method was using a slash, first used for Kirk/Spock. This is today mainly used for same-sex ships; fanfiction with these pairings is known as slash fiction.
Name blending is often used to refer to a couple, like 'Reylo' for Kylo Ren and Rey in Star Wars franchise, 'Destiel' for Dean Winchester and Castiel in the Supernatural TV series, and 'Bubbline' referring to Princess Bubblegum and Marceline the Vampire Queen in Adventure Time. Portmanteaus and clipped compounds are used not only to abbreviate character pairings but also to create a name for the ship itself. For example, 'Klance' forms a clipped compound, and an abbreviated form of the complete names Keith and Lance in Voltron: Legendary Defender. 'Sculder' in this case Dana Scully and Fox Mulder in The X-Files, is an example of surnames being blended, although most X-Files fans use the term "MSR" (Mulder-Scully Relationship), as is "MoonBoon" to stand for Zarya Moonwolf and Kitty Boon in Mysticons. In other cases, first names of characters are merged, like the ships for Marcy Wu and Anne Boonchuy (Marcanne), Sasha Waybright and Marcy Wu (Sasharcy), and Sasha Waybright and Anne Boonchuy (Sashanne) in Amphibia. These combinations of names often follow systematic phonological principles, in which the first character in the ship's name is seen as the 'dominant' partner. Japanese ship naming conventions often attach names together without slashing or blending by using an XY name-name format. This format is ruled by boy-girl ordering, or seme-uke (top-bottom) in Yaoi. In many East Asian countries there is a distinct difference between the pairing of XY and YX. Such as the pairing names of 'MomoYuki' (where Momo is dominant) vs. 'YukiMomo' (where Yuki is dominant) from the series Idolish7.
Many fandom-specific variants exist and often use fandom-specific terminology. These often employ words that describe the relationship between characters in the context of the fictional universe and simply add the word "Shipping" to the end. Other terminology include using a combination of the characters' names and codes as a ship name. For instance, ship names for characters in RWBY include "Bumbleby" (Blake Belladonna and Yang Xiao Long) and "White Rose" (Weiss Schnee and Ruby Rose).