From Fan History Wiki
Het is an abbreviation for heterosexual, and is used to label a story as having a straight couple as the main pairing.
- alt.sex newsgroup on February 16, 1994, Claire Maier uses the term "het" in an interjectory conversation about slash. In context, the poster was talking about fans rather than fandoms or genres, but it's the earliest citable reference linking the term and fandom found via publicly accessible search.
- December 11, 1995, on the rec.arts.sf.tv newsgroup, a Blake's 7 poster Reba Bandyopadhyay put out a zine call for submissions announcement references acceptence of both "het" and "homo" themed work: (2) Adult material: We do not mind having 'adult' material (whether het or homo). HOWEVER, we will NOT be accepting sexually explicit work of any kind." The zine, The Aquitar Files, was supposedly, The First Ever _Blake's 7_ WWW Zine!!
- September 6, 1996, Ruth Gifford references "het" as being "sometimes" used as part of the rating sysstem in the FAQ for the alt.sex.fetish.startrek newsgroup.
- As early as 1997 "het" was being used a descriptor in newsgroups to delineate heterosexual Fan fiction from other genres, including slash, which indicates the gen or traditional m/f pairings default for Fan fiction were already out of use. ~ Source: alt.tv.highlander 
- In June 2007, Mary Ellen Curtin estimated that between fifty and sixty percent of all fan fiction was het. 
- het, adj. Refers to fanfic featuring or fictional situations depicting two people of different genders romantically and/or sexually involved. May also refer to fanfic with protagonists recognizably straight (in the modern sense), although the presence or absence of straight characters is not usually considered worthy of remark. 
- Gen/Het/Slash: categories of fan fiction, used in a wide variety of fandoms. "Gen" is short for "General" and refers to any and all stories that aren't centered on sexual or romantic relationships. "Het" refers to a story centered on a heterosexual relationship, though it's a less common term than the other two. "Slash" refers to a story centered on a same-sex pairing. It originates from Star Trek stories featuring the Kirk/Spock relationship, but applies to female/female as well as male/male pairings. Slash is hard to do well. It's the redheaded stepchild of fan fiction, and is banned from certain lists. Check for clearance before you post. 
- het: short for heterosexual (as in het UC, het smut, het foof) 
- Het: Sometimes short for "heterosexual sex/relationships/situations".
- Het: Heterosexual relationships (girls with boys)
- Heterosexual fanfic is usually called "het".
- het: Short for 'heterosexual', denoting fan fiction that features either implied or bluntly portrays a heterosexual relationship between two or more characters. 
- HET: Story or fanzine with explicit scenes of heterosexual sexual acts. See also: SLASH and GEN.
- Het: Heterosexual love (boy x girl) 
Below, sorted by fandom, are examples of hetfic.
- The Last Embrace by Kristen Elizabeth featuring the male Gil Grissom involved with the female Sara Sidle
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