The OHO Group, a Slovene art collective active from 1966-1971 in Ljubljana. Members included Marko Pogačnik, Iztok Geister Plamen, Marjana Ciglič, Milenko Matanović, Andraž Šalamun, Tomaž Šalamun, David Nez, Matjaž Hanšek, Naško Križnar, Vojin Kovač Chubby, Aleš Kermavner, Franci Zagoričnik, Marika Pogačnik, Zvona Ciglič, Nuša and Srečo Dragan, a.o.
The members of the OHO group developed various strategies and approaches that they first called “reism,” a type of arte povera, land art and body art, processual and conceptual art. They aspired to “liberate” situations and objects and present them to the public outside of their fixed functions. The term “Oho” refers to the observation of forms (with the eye, “oko”, and ear, “uho”) in their immediate presence, and is also an exclamation of astonishment, said Marko Pogačnik, the group’s leader: “Because when we uncover the essence of a thing, that is when we exclaim ‘oho’.” A specific approach toward objects, a distancing from the weight of meaning, is apparent in Edicija Oho (Oho Edition), where literature and visual art are reduced to objectivity. Artists such as Pogačnik, Geister, Hanžek, Matanović, Dreja and others created their “books” by printing objects, drawings and sentences on single pages placed in small boxes. These books are objects, with their pages being various forms that can be handled, jumbled letters that must be arranged to form a sentence. A book should be heard, looked through. It is an “open work,” one which, demonstrating “reistic” tautology, suggests a game. (Source)
Igor Zabel on OHO
A particularly important phenomenon in the second half of the 60s and early 70s was the avant-garde group OHO. The development of the group can be divided into three rather different phases. The first was centred around the notion of Reism (from the Latin word „res", i.e. „thing"). The members of OHO wanted to develop a radically different relationship towards the world: instead of a humanistic position, which implies a world of objects dominated by the subject, they wanted to achieve a world of things, where there would be no hierarchical (or indeed any) difference between people and things; the correct relationship towards such a world is not action, but observing. OHO used a number of media (and their in-between forms), drawings, photographs, film, video (the first video works in Slovenia were produced in this context by Nuša and Srečo Dragan), music, texts, but also the way of dressing, living and behaviour, to redirect the awareness of people into Reistic observing. It is clear that they criticised the traditional division between art and life (they wanted to deprive art of its aura and to enter every-day life with small products, sometimes sold on the streets – such as matchboxes for which they produced several series of labels and which were sold simply for the price of a matchbox), as well as the idea of the creative personality (they tried to substitute the artistic will and deliberate procedures with accident, absurd or pre-determined mathematical programmes). In the second phase, the group established a dialogue with the contemporary artistic avant-garde: the artists used the principles of Arte Povera, Process Art, Land Art, Body Art and Conceptual Art. It is interesting, for example, to observe the opposition between the American Earthworks and OHO Land Art works: these were small-scale, ephemeral, done with simple tools in a cultivated landscape, and often very minimal, mild and poetic. Such a relationship was one of the starting points for the third phase of OHO’s work, which represented a combination of Concept Art and a kind of esoteric and ecological approach. The subject of the work was a harmonic unity between the members of the group, but also of the group and nature and even the universe as a whole. In the search for such a harmony, they used different means, including telepathy. The group was just starting an international career when the members decided they should abandon art as a separate area and really enter life; therefore, they settled on an abandoned farm and started a community.
Source: Igor Zabel, "Art in Slovenia since 1945".
- Grupa OHO, 1966-1971, Belgrade: Muzej savremene umetnosti, 1979,  pp. With text by Tomaž Brejc. (Serbo-Croatian)
- Groups Gorgona & OHO From Yugoslavia. XVI São Paulo Biennial, 1981. (English)
- OHO: Retrospektiva/Eine Retrospektive/A Retrospective, ed. Igor Zabel, Ljubljana: Moderna Galerija, 1994, 120 pp; new ed., Ljubljana: Moderna Galerija, and Frankfurt am Main: Revolver, 2007, 167 pp. Exh. held at Moderna galerija Ljubljana, 1 Feb-13 Mar 1994; Neue Galerie am Landesmuseum Joanneum, Graz, 18 Aug-18 Sep 1994. (Slovenian)/(German)/(English)
- in Milenko Matanović, David Nez, Andraž Šalamun, Tomaž Šalamun, Zagreb: Gallery of Contemporary Art in Zagreb, 1969. (Serbo-Croatian)
- "An Interview with Milenko Matanović and Tomaž Šalamun", trans. Aleksandar Bošković and Jennifer Zoble, post, New York: MoMA, 6 Sep 2016. (English)
- Beti Žerovc, "The OHO Files, Updated", ArtMargins, Oct 2011; exp., 15 Aug 2013. Features interviews with David Nez, Milenko Matanović, Andraž Šalamun, and Marko Pogačnik. (English)
- Ješa Denegri, "Primjeri konceptualne umjetnosti u Jugoslaviji", Život umjetnosti 15-16, Zagreb, 1971, pp 147-152. (Serbo-Croatian)
- Igor Zabel, "A Short History of OHO", in East Art Map; Contemporary Art and Eastern Europe, ed. IRWIN, London: Afterall, 2006, pp 410-432. (English)
- Miško Šuvaković, Skrite zgodovine skupine OHO, Ljubljana: P.A.R.A.S.I.T.E., 2009, 144 pp. Exh. held at P74 Center and Gallery, Ljubljana, 23 Apr-21 May 2009.  (Slovenian)
- The Clandestine Histories of the OHO Group: A Cold War Era Transgressive and Subversive Artistic Practice; Transgression, Sexuality, and Politics in the Pursuits of the OHO Group and the Movement OHO-Katalog, 1965-1971, trans. Irena Sentevska, Ljubljana: P.A.R.A.S.I.T.E., 2010, 149 pp.   (English)
- Dogodek / The Event; 29. grafični bienale / The 29th Biennial of Graphic Arts, eds. Peter Kisin and Beti Žerovc, Ljubljana: Mednarodni grafični likovni center, 2011, pp 182-193. (Slovenian)/(English)
- Marko Pogačnik: Umetnost življenja – življenje umetnosti / The Art of Life – The Life of Art, ed. Igor Španjol, Ljubljana: Moderna galerija, 2012. (Slovenian)/(English)
- Milena Tomić, "Re-enacting OHO: Some Interventions in a Neo-avant-garde Field", Object 14, London, 2012, pp 100-125. (English)
- Igor Zabel, "'OKHO': ot reizma k kontseptualizmu" [«OXO» — от реизма к концептуализму], trans. Maria Rogulova, Moscow Art Magazine 91, Moscow, 2015. (Russian)
- Ksenya Gurshtein, "The OHO Group, 'Information', and Global Conceptualism avant la lettre", Part 2, Part 3, post, New York: MoMA, 25 Aug-15 Sep 2016. (English)