LGBT and GLBT are initialisms that stand for lesbian, gay, bisexual, and transgender. In use since the 1990s, the term is an adaptation of the initialism LGB, which was used to replace the term gay in reference to the LGBT community beginning in the mid-to-late 1980s. Activists believed that the term gay community did not accurately represent all those to whom it referred.
The initialism has become mainstream as a self-designation; it has been adopted by the majority of sexuality and gender identity-based community centers and media in the United States, as well as some other English-speaking countries. The term is also used in dozens of other countries.
The initialism LGBT is intended to emphasize a diversity of sexuality and gender identity-based cultures. It may be used to refer to anyone who is non-heterosexual or non-cisgender, instead of exclusively to people who are lesbian, gay, bisexual, or transgender. To recognize this inclusion, a popular variant adds the letter Q for those who identify as queer or are questioning their sexual identity; LGBTQ has been recorded since 1996. Those who add intersex people to LGBT groups or organizing use an extended initialism LGBTI. Some people combine the two acronyms and use the term LGBTIQ or LGBTQI. Others use LGBT+ to encompass spectrums of sexuality and gender.
History of the term
Before the sexual revolution of the 1960s, there was no common non-derogatory vocabulary for non-heterosexuality; the closest such term, third gender, traces back to the 1860s but never gained wide acceptance in the United States.
The first widely used term, homosexual, originally carried negative connotations. It was replaced by homophile in the 1950s and 1960s, and subsequently gay in the 1970s; the latter term was adopted first by the homosexual community. Lars Ullerstam (sv) promoted use of the term sexual minority in the 1960s, as an analogy to the term ethnic minority for non-whites.
As lesbians forged more public identities, the phrase "gay and lesbian" became more common. The Daughters of Bilitis folded in 1970 due to disputes over their direction: whether to focus on feminism or gay rights issues. As equality was a priority for lesbian feminists, disparity of roles between men and women or butch and femme were viewed as patriarchal. Lesbian feminists eschewed gender role play that had been pervasive in bars, as well as the perceived chauvinism of gay men; many lesbian feminists refused to work with gay men, or take up their causes.
Lesbians who held a more essentialist view, that they had been born homosexual and used the descriptor "lesbian" to define sexual attraction, often considered the separatist, angry opinions of lesbian-feminists to be detrimental to the cause of gay rights. Bisexual and transgender people also sought recognition as legitimate categories within the larger minority community.
After the elation of change following group action in the 1969 Stonewall riots in New York City, in the late 1970s and the early 1980s, some gays and lesbians became less accepting of bisexual or transgender people. Critics said that transgender people were acting out stereotypes and bisexuals were simply gay men or lesbian women who were afraid to come out and be honest about their identity. Each community has struggled to develop its own identity including whether, and how, to align with other gender and sexuality-based communities, at times excluding other subgroups; these conflicts continue to this day. LGBTQ activists and artists have created posters to raise consciousness about the issue since the movement began.
From about 1988, activists began to use the initialism LGBT in the United States. Not until the 1990s within the movement did gay, lesbian, bisexual and transgender people gain equal respect . Although the LGBT community has seen much controversy regarding universal acceptance of different member groups (bisexual and transgender individuals, in particular, have sometimes been marginalized by the larger LGBT community), the term LGBT has been a positive symbol of inclusion.
Despite the fact that LGBT does not nominally encompass all individuals in smaller communities (see Variants below), the term is generally accepted to include those not specifically identified in the four-letter initialism. Overall, the use of the term LGBT has, over time, largely aided in bringing otherwise marginalized individuals into the general community. Transgender actress Candis Cayne in 2009 described the LGBT community "the last great minority", noting that "We can still be harassed openly" and be "called out on television".
In response to years of lobbying from users and LGBT groups to eliminate discrimination, the online social networking service Facebook, in February 2014, widened its choice of gender variants for users. 
Many variants exist including variations that change the order of the letters; LGBT or GLBT are the most common terms and the ones most frequently seen. Although identical in meaning, LGBT may have a more feminist connotation than GLBT as it places the "L" (for "lesbian") first. LGBT may also include additional Q's for "queer" or "questioning" (sometimes abbreviated with a question mark and sometimes used to mean anybody not literally L, G, B or T) producing the variants "LGBTQ" and "LGBTQQ"". In the United Kingdom, it is sometimes stylized as LGB&T, whilst the Green Party of England and Wales uses the term LGBTIQ in its manifesto and official publications.
The order of the letters has not been standardized; in addition to the variations between the positions of the initial "L" or "G", the mentioned, less common letters, if used, may appear in almost any order. Initialisms related to LGBTQ people are sometimes referred to as "alphabet soup". Variant terms do not typically represent political differences within the community, but arise simply from the preferences of individuals and groups.
The gender identity "transgender" has been recategorized to trans* by some groups, where trans (without the asterisk) has been used to describe trans men and trans women, while trans* covers all non-cisgender (genderqueer) identities, including transgender, transsexual, transvestite, genderqueer, genderfluid, non-binary, genderfuck, genderless, agender, non-gendered, third gender, two-spirit, bigender, and trans man and trans woman. Likewise, the term transsexual commonly falls under the umbrella term transgender, but some transsexual people object to this.
The relationship of intersex to lesbian, gay, bisexual and trans, and queer communities is complex, but intersex people are often added to the LGBT category to create an LGBTI community. Some intersex people prefer the initialism LGBTI, while others would rather that they not be included as part of the term. LGBTI is used in all parts of "The Activist's Guide" of the Yogyakarta Principles in Action. Emi Koyama describes how inclusion of intersex in LGBTI can fail to address intersex-specific human rights issues, including creating false impressions "that intersex people's rights are protected" by laws protecting LGBT people, and failing to acknowledge that many intersex people are not LGBT. Organisation Intersex International Australia states that some intersex individuals are same sex attracted, and some are heterosexual, but "LGBTI activism has fought for the rights of people who fall outside of expected binary sex and gender norms." Julius Kaggwa of SIPD Uganda has written that, while the gay community "offers us a place of relative safety, it is also oblivious to our specific needs".
Numerous studies have shown higher rates of same sex attraction in intersex people, with a recent Australian study of people born with atypical sex characteristics finding that 52% of respondents were non-heterosexual, thus research on intersex subjects has been used to explore means of preventing homosexuality. As an experience of being born with sex characteristics that do not fit social norms, intersex can be distinguished from transgender, while some intersex people are both intersex and transgender.
Some use the much shorter style LGBT+ to mean "LGBT and related communities". LGBTQIA, which is used, for example, by the "Lesbian, Gay, Bisexual, Transgender, Queer, Intersex, Asexual Resource Center" at the University of California, Davis.
Other variants may have a "U" for "unsure"; a "C" for "curious"; another "T" for "transvestite"; a "TS", or "2" for "two-spirit" persons; or an "SA" for "straight allies". However, the inclusion of straight allies in the LGBT acronym has proven controversial as many straight allies have been accused of using LGBT advocacy to gain popularity and status in recent years, and various LGBT activists have criticised the heteronormative worldview of certain straight allies. Some may also add a "P" for "polyamorous", an "H" for "HIV-affected", or an "O" for "other". Furthermore, the initialism LGBTIH has seen use in India to encompass the hijra third gender identity and the related subculture.
The initialism LGBTTQQIAAP (lesbian, gay, bisexual, transgender, transsexual, queer, questioning, intersex, asexual, ally, pansexual) has also resulted, although such initialisms are sometimes criticized for being confusing and leaving some people out, as well as issues of placement of the letters within the new title. However, adding the term "allies" to the initialism has sparked controversy, with some seeing the inclusion of "ally" in place of "asexual" as a form of asexual erasure. There is also the acronym QUILTBAG (queer and questioning, intersex, lesbian, transgender and two-spirit, bisexual, asexual and ally, and gay and genderqueer).
Criticism of the term
The initialisms LGBT or GLBT are not agreed to by everyone that they encompass. For example, some argue that transgender and transsexual causes are not the same as that of lesbian, gay, and bisexual (LGB) people. This argument centers on the idea that transgenderism and transsexuality have to do with gender identity, or a person's understanding of being or not being a man or a woman irrespective of their sexual orientation. LGB issues can be seen as a matter of sexual orientation or attraction. These distinctions have been made in the context of political action in which LGB goals, such as same-sex marriage legislation and human rights work (which may not include transgender and intersex people), may be perceived to differ from transgender and transsexual goals. Another problem associated is that people may not always identify with the given labels. One study conducted in Australia discovered that all the participants had experienced microaggressions, bullying and anti-social behaviours. However, not all of the participants believed their victimisation to be motivated by anti-LGBTIQ beliefs. What it did establish is that many of these microaggressions occurred due to misconceptions and conflicting opinions on what these labels entailed (in particular, transsexual and bisexual). Evidently, by placing blanket labels on many people, who all experience difference narratives, there are inconsistencies.
A belief in "lesbian & gay separatism" (not to be confused with the related "lesbian separatism"), holds that lesbians and gay men form (or should form) a community distinct and separate from other groups normally included in the LGBTQ sphere. While not always appearing of sufficient number or organization to be called a movement, separatists are a significant, vocal, and active element within many parts of the LGBT community. In some cases separatists will deny the existence or right to equality of nonmonosexual orientations and of transsexuality. This can extend to public biphobia and transphobia. In contrasts to separatists, Peter Tatchell of the LGBT human rights group OutRage! argues that to separate the transgender movement from the LGB would be "political madness", stating that "Queers are, like transgender people, gender deviant. We don't conform to traditional heterosexist assumptions of male and female behaviour, in that we have sexual and emotional relationships with the same sex. We should celebrate our discordance with mainstream straight norms."
The portrayal of an all-encompassing "LGBT community" or "LGB community" is also disliked by some lesbian, gay, bisexual, and transgender people. Some do not subscribe to or approve of the political and social solidarity, and visibility and human rights campaigning that normally goes with it including gay pride marches and events. Some of them believe that grouping together people with non-heterosexual orientations perpetuates the myth that being gay/lesbian/bi/asexual/pansexual/etc. makes a person deficiently different from other people. These people are often less visible compared to more mainstream gay or LGBT activists. Since this faction is difficult to distinguish from the heterosexual majority, it is common for people to assume all LGBT people support LGBT liberation and the visibility of LGBT people in society, including the right to live one's life in a different way from the majority. In the 1996 book Anti-Gay, a collection of essays edited by Mark Simpson, the concept of a 'one-size-fits-all' identity based on LGBT stereotypes is criticized for suppressing the individuality of LGBT people.
Writing in the BBC News Magazine in 2014, Julie Bindel questions whether the various gender groupings now, "bracketed together" ... "share the same issues, values and goals?" Bindel refers to a number of possible new initialisms for differing combinations and concludes that it may be time for the alliances to be reformed or finally go "our separate ways".
Many people have looked for a generic term to replace the numerous existing initialisms. Words such as queer (an umbrella term for sexual and gender minorities that are not heterosexual, or gender-binary) and rainbow have been tried, but most have not been widely adopted. Queer has many negative connotations to older people who remember the word as a taunt and insult and such (negative) usage of the term continues. Many younger people also understand queer to be more politically charged than LGBT. "Rainbow" has connotations that recall hippies, New Age movements, and groups such as the Rainbow Family or Jesse Jackson's Rainbow/PUSH Coalition. SGL ("same gender loving") is sometimes favored among gay male African Americans as a way of distinguishing themselves from what they regard as white-dominated LGBT communities.
Some people advocate the term "minority sexual and gender identities" (MSGI, coined in 2000), or gender and sexual/sexuality minorities (GSM) so as to explicitly include all people who are not cisgender and heterosexual, or gender, sexual, and romantic minorities (GSRM) which is more explicitly inclusive of minority romantic orientations and polyamory, but those have not been widely adopted either. Other rare umbrella terms are Gender and Sexual Diversities (GSD), MOGII (Marginalized Orientations, Gender Identities, and Intersex) and MOGAI (Marginalized Orientations, Gender Alignments and Intersex).
The National Institutes of Health have framed LGBT, others "whose sexual orientation and/or gender identity varies, those who may not self-identify as LGBT" and also intersex populations (as persons with disorders of sex development) as "sexual and gender minority" (SGM) populations. This has led to the development of an NIH SGM Health Research Strategic Plan. The Williams Institute has used the same term in a report on an international sustainable development goals, but excluding intersex populations.
In public health settings, MSM ("men who have sex with men") is clinically used to describe men who have sex with other men without referring to their sexual orientation, with WSW ("women who have sex with women") also used as a corollary.
- LGBT retirement issues
- LGBT rights by country or territory
- LGBT rights opposition
- LGBT social movements
- LGBT symbols
- List of LGBT periodicals
- List of LGBT-related organizations and conferences
- List of transgender-related topics
- Queer theology
- Racism in the LGBT community
- Stigma management
- Acronyms, Initialisms & Abbreviations Dictionary, Volume 1, Part 1. Gale Research Co., 1985, ISBN 978-0-8103-0683-7.
- Swain, Keith W. (21 June 2007). . Denver Post. Retrieved 2008-07-05.
- Centerlink. (PDF). LGBT Movement Advancement Project. Retrieved August 29, 2008.
- . nlgja.org. 2008.
- Zak, Emily (1 October 2013). . Ms. Blog. Liberty Media. Retrieved 16 July 2017.
- Shankle, Michael D. (2006). . Haworth Press. ISBN 1-56023-496-2.
- . Books.google.com. 2008-11-01. Retrieved 2011-10-23.
- William L. Maurice, Marjorie A. Bowman, , Mosby Year Book, 1999, ISBN 978-0-8151-2797-0
- Aragon, Angela Pattatuchi (2006). . Haworth Press. ISBN 1-56023-645-0. Retrieved 2008-07-05.
- Cahill, Sean, and Bryan Kim-Butler. "Policy priorities for the LGBT community: Pride Survey 2006." New York, NY: National Gay and Lesbian Task Force (2006).
- Ross, E. Wayne (2006). . SUNY Press. ISBN 0-7914-6909-3.
- Kennedy, Hubert C. (1980) "The "third sex" theory of Karl Heinrich Ulrichs", Journal of Homosexuality. 1980–1981 Fall–Winter; 6(1–2): pp. 103–1
- Hirschfeld, Magnus, 1904. Berlins Drittes Geschlecht ("Berlin's Third Sex")
- Ellis, Havelock and Symonds, J. A., 1897. Sexual Inversion.
- Carpenter, Edward, 1908. .
- Duc, Aimée, 1901. Sind es Frauen? Roman über das dritte Geschlecht ("Are These Women? Novel about the Third Sex")
- Minton, Henry (2002). . University of Chicago Press. ISBN 0-226-53043-4. Retrieved 2009-01-01.
- Ullerstam, Lars (1967). . Retrieved 12 March 2015.
- Esterberg, Kristen (1994). "From Accommodation to Liberation: A Social Movement Analysis of Lesbians in the Homophile Movement". Gender and Society. 8 (3): 424–443.
- Faderman, Lillian (1991). Odd Girls and Twilight Lovers: A History of Lesbian Life in Twentieth Century America, Penguin Books. ISBN 0-14-017122-3, p. 210–211.
- Faderman (1991), p. 217–218.
- Leli, Ubaldo; Drescher, Jack (2005). . Haworth Press. ISBN 0-7890-2576-0.
- Alexander, Jonathan; Yescavage, Karen (2004). . Haworth Press. ISBN 1-56023-287-0.
- . Center for the Study of Political Graphics. Retrieved 1 October 2016.
- , American Educational Research Association Verlag AERA, 1988.
- "I Advocate..". The Advocate. Issue #1024. March 2009. p. 80.
- . The Guardian. 14 February 2014. Retrieved 21 May 2014.
- Dewey, Caitlin (14 February 2014). . Washington Post. Retrieved 21 May 2014.
- Nicole Morley (26 June 2015). . Metro.
- Ring, Trudy. . Advocate. Retrieved 30 October 2016.
- (in Spanish). Comisión Organizadora de la Marcha (C.O.M.O). Retrieved December 2, 2016.
- Bloodsworth-Lugo, Mary K. (2007). . SUNY Press. ISBN 0-7914-7221-3.
- Alder, Christine; Worrall, Anne (2004). . SUNY Press. ISBN 0-7914-6110-6.
- Cherland, Meredith Rogers; Harper, Helen J. (2007). . Routledge. ISBN 0-8058-5056-2.
- . International Lesbian, Gay, Bisexual, Trans and Intersex Association. 26 September 2014. Retrieved 14 April 2015.
- . The National LGB&T Partnership. Retrieved 14 April 2015.
- . Lgbtiq-greens.greenparty.org.uk. 17 May 2011. Retrieved 25 May 2011.
- (PDF). Green Party of England and Wales. Retrieved 3 May 2015.
- Duffy, Nick (1 May 2015). . PinkNews. Retrieved 3 May 2015.
- . PugetSoundOff.org. Retrieved 6 October 2014.
- DeMarco, Linda; Bruni, Sylvain (18 July 2012) [1st pub. 18 May 2012]. . The Huffington Post. 1527958. from the original on 3 February 2015.
- Brown, Catrina; Augusta-Scott, Tod (2006). . Sage Publications Inc. ISBN 1-4129-0988-0.
- Ryan, Hugh (10 January 2014). . Slate. Retrieved 21 May 2014.
- . Vaden Health Center Stanford University. 14 February 2014. Retrieved 21 May 2014.
- Bohan, Janis S. (1996). . Routledge. ISBN 0-415-91514-7.
- Dreger, Alice (4 May 2015). (PDF). Association of American Medical Colleges. Retrieved 18 May 2016.
- Makadon, Harvey J.; Mayer, Kenneth H.; Potter, Jennifer; Goldhammer, Hilary (2008). . ACP Press. ISBN 1-930513-95-X.
- . Ypinaction.org. Retrieved 2011-10-23.
- Koyama, Emi. . Intersex Initiative. Retrieved 18 May 2016.
- . 21 November 2012. Retrieved 18 May 2016.
- , Intersex for allies and Making services intersex inclusive by Organisation Intersex International Australia, via Gay News Network, 2 June 2014.
- Kaggwa, Julius (September 19, 2016). . The Guardian. ISSN . Retrieved 2016-10-03.
- Meyer-Bahlburg, Heino F.L. (January 1990). . Journal of Child and Adolescent Psychopharmacology. 1 (4): 279–283. doi:. ISSN . Retrieved 18 May 2016.
human studies of the effects of altering the prenatal hormonal milieu by the administration of exogenous hormones lend support to a prenatal hormone theory that implicates both androgens and estrogens in the development of gender preference ... it is likely that prenatal hormone variations may be only one among several factors influencing the development of sexual orientation
- Dreger, Alice; Feder, Ellen K; Tamar-Mattis, Anne (29 June 2010), , The Hastings Center Bioethics Forum, retrieved 18 May 2016
- . Organisation Intersex International Australia. February 3, 2016. Retrieved 2016-08-18.
- Jones, Tiffany; Hart, Bonnie; Carpenter, Morgan; Ansara, Gavi; Leonard, William; Lucke, Jayne (2016). (PDF). Cambridge, UK: Open Book Publishers. ISBN 978-1-78374-208-0. Archived from (PDF) on 14 September 2016. Retrieved 2 February 2016.
- (PDF). United Nations Office of the High Commissioner for Human Rights. 2015. Retrieved 28 March 2016.
- , Council of Europe Parliamentary Assembly, Report Doc. 13297, 6 September 2013.
- . Inter/Act. Retrieved 2013-07-10.
- . Organisation Intersex International Australia. Retrieved 2013-07-10.
- Cabral Grinspan, Mauro (October 25, 2015), , Intersex Day
- . University of California, Davis. September 21, 2015. Retrieved 2017-01-20.
- Lebaron, Sarah; Pecsenye, Jessica; Roland, Becerra; Skindzier, Jon (2005). . College Prowler, Inc. ISBN 1-59658-092-5.
- Chen, Edith Wen-Chu; Omatsu, Glenn (2006). . Rowman & Littlefield. ISBN 0-7425-5338-8.
- Babb, Florence E. (2001). . University of Texas Press. ISBN 0-292-70900-5.
- Padilla, Yolanda C. (2003). . Haworth Press. ISBN 1-56023-275-7.
- Swigonski, Mary E.; Mama, Robin S.; Ward, Kelly; Shepard, Matthew (2001). . Haworth Press. ISBN 1-56023-257-9.
- Becker, Ron (2006). "Gay-Themed Television and the Slumpy Class: The Affordable, Multicultural Politics of the Gay Nineties". Television & New Media. Sage Publications. 7 (2): 184–215. doi:. ISSN . (Subscription required (. ))
- DeTurk, Sara (2011). "Allies in Action: The Communicative Experiences of People Who Challenge Social Injustice on Behalf of Others". Communication Quarterly. 59 (5): 569–590. doi:. ISSN . (Subscription required (. ))
- O'Rourke, P. J. (2001). . Grove Press. ISBN 0-8021-4198-6.
- Gurjar, Kaumudi. . punemirror.in. Pune Mirror. Retrieved 22 December 2014.
- McCusker, Ros. . gayleeds.com. Retrieved 22 December 2014.
- Kelly, Morgan. . iowastatedaily.com. Iowa State Daily. Retrieved 29 December 2014.
- Richard, Katherine. . loyolamaroon.com. The Maroon. Archived from on 6 December 2013. Retrieved 29 December 2014.
That "A" is not for allies[,] [t]hat "A" is for asexuals. [...] Much like bisexuality, asexuality suffers from erasure.
- . Apex Magazine. Retrieved 6 October 2014.
- Klesse, Christian (2007). . Ashgate Publishing, Ltd. ISBN 0-7546-4906-7.
- Finnegan, Dana G.; McNally, Emily B. (2002). . Haworth Press. ISBN 1-56023-925-5.
- Wilcox, Melissa M. (2003). . Indiana University Press. ISBN 0-253-21619-2.
- "James Roffee & Andrea Waling Rethinking microaggressions and anti-social behaviour against LGBTIQ+ Youth". Safer Communities. 15: 190–201. doi:.
- Mohr, Richard D. (1988). . Columbia University Press. ISBN 0-231-06735-6. Retrieved 2008-07-05.
- Atkins, Dawn (1998). . Haworth Press. ISBN 0-7890-0463-1.
- Blasius, Mark (1994). . Temple University Press. ISBN 1-56639-173-3.
- Tatchell, Peter (24 June 2009). . mother-ship.com. Mothership Blog. Archived from on 3 July 2009. Retrieved 18 March 2015.
To try and separate the LGB from the T, and from women, is political madness. Queers are, like transgender people, gender deviant. We don’t conform to traditional heterosexist assumptions of male and female behaviour, in that we have sexual and emotional relationships with the same sex. We should celebrate our discordance with mainstream straight norms. The right to be different is a fundamental human right. The idea that we should conform to straight expectations is demeaning and insulting.
- Sycamore, Matt Bernstein (2005). . Soft Skull Press. ISBN 1-932360-56-5. Retrieved 2008-07-05.
- Carlsson, Chris (2005). . City Lights Books. ISBN 1-931404-05-4. Retrieved 2008-07-05.
- Leondar-Wright, Betsy (2005). . New Society Publishers. ISBN 0-86571-523-8.
- . Marksimpson.com. Archived from on September 27, 2011. Retrieved 2011-10-23.
- Julie Bindel (2 July 2014). . BBC News Magazine. Retrieved 4 July 2014.
- Armstrong, Elizabeth A. (2002). . University of Chicago Press. ISBN 0-226-02694-9. Retrieved 2008-07-05.
- Halpin, Mikki (2004). . Simon and Schuster. ISBN 0-689-87448-0.
- Rimmerman, Craig A.; Wald, Kenneth D.; Wilcox, Clyde (2006). . University of Chicago Press. ISBN 1-4129-0988-0.
- . Bradford Uni MSGI Society. 2008. Retrieved 2008-09-09.
- . acronymfinder.com. Retrieved 6 October 2014.
- . The Huffington Post. 19 September 2013. Retrieved 6 October 2014.
- . queerumich.com. University of Michigan (on Tumblr). Retrieved 12 March 2015.
- . University of Derby. Retrieved 12 March 2015.
- , February 25, 2013
- . The Huffington Post. 25 February 2013. Retrieved 6 October 2014.
- . Dalhousie News. Retrieved 6 October 2014.
- Alexander, Rashada; Parker, Karen; Schwetz, Tara (October 2015). . LGBT Health. doi:. ISSN .
- Park, Andrew (June 2016). A Development Agenda for Sexual and Gender Minorities. The Williams Institute.
- Young, R M & Meyer, I H (2005) The Trouble with "MSM" and "WSW": Erasure of the Sexual-Minority Person in Public Health Discourse American Journal of Public Health July 2005 Vol. 95 No. 7.
- Glick, M Muzyka, B C Salkin, L M Lurie, D (1994) Necrotizing ulcerative periodontitis: a marker for immune deterioration and a predictor for the diagnosis of AIDS Journal of Periodontology 1994 65 p. 393–397.