Austria

• Austrian Geographical Society
  Letter of support 

Belgium

• Groupe Interclub de Perfectionnement par la Spéléologie
  Letter of support

• Domaine des Grottes de Han
  Letter of support

Botswana

• Department of National Museum and Monuments
  Letter of support

Bulgaria

• Bulgaria, The Bulgarian Association for Cave and Eco Tourism (BAPET/БАПЕТ)
  
  

Brazil

• São Paulo State Speleological Heritage Council
  Letter of support

• “Pascoal Andreta” Cultural Foundation
  Letter of support

• Center of Studies on Subterranean Biology
  Letter of support

• Brazilian Bat Research Society
  Letter of support

• Conselho Federal de Biologia (Federal Council of Biology)
  Letter of support

Canada

• Royal Canadian Geographical Society
  Letter of support

• Bulkley Valley Research Centre
  Letter of support

China

• Guizhou Institute of Mountain Resources
  Letter of support

• International Research Center on Karst Under the Auspices of UNESCO
  Letter of support

• Institute of Hydrobiology, Chinese Academy of Sciences
  Letter of support

Croatia

• Institute for Environment and Nature, Ministry of Environmental Protection and Green Transition Letter of support

• Croatian Academy of Sciences and Arts (HAZU)
  Letter of support

• Croatian Geomorphological Society
  Letter of support

• Croatian Geographical Society
  Letter of support

• Croatian Geotechnical Society
  Letter of support

• Croatian Geological Society
  Letter of support

• University of Zagreb, Faculty of Sciences
  Letter of support

• University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering
  Letter of support

• University of Zagreb, Department of Geography FS
  Letter of support

Czech Republic

• Czech Association of Geomorphologists
  Letter of support

• Institute of Geology of the Czech Academy of Sciences
  Letter of support

France

• French Association of Karstology (AFK)
  Letter of support

Germany

• German League for Nature, Animal and Environment Protection (DNR)
  Letter of support

• Bavarian Academy of Science (BAdW)
  Letter of support

Indonesia

• Faculty of Geography, Universitas Gadjah Mada
  Letter of support

Iraq

• Iraqi Geoheritage and Archaeology Heritage Society
  Letter of support

• Iraq Geological Survey
  Letter of support

• Iraqi Natural History Research Centre and Museum
  Letter of support

• Kurdistan Geopark Association
  Letter of support

• The Geological Society of Kurdistan Region
  Letter of support

• University of Baghdad, Department of Scholarships and Cultural Relations
  Letter of support

• Al Muthanna University, college of Science
  Letter of support

• University of Sulaimani, Department of Earth Sciences and Petroleum
  Letter of support
  
  

Italy

• Italian Speleological Institute
  Letter of support

• Italian Society of Environmental Geology (SIGEA)
  Letter of support

• Italian Geological Society (SGI)
  Letter of support

• Italian Society of Mineralogy and Petrology (SIMP)
  Letter of support

• Geological Survey of Italy (ISPRA)
  Letter of support

• Apulian Speleological federation (FSP)
  Letter of support

• Club Alpinistico Triestino (APS)
  Letter of support

• DISTEGEO, Earth and Environmental Sciences Department at the University Aldo Moro, Bari Letter of support

• Alta Murgia National Park
  Letter of support

• Le Taddarite speleological association
  Letter of support

• Milan's Caving Association (GGM)
  Letter of support

• Speleological Federation of Abruzzo (FSA)
  Letter of support

• Sicilian Regional Speleological Federation (FSRS)
  Letter of support

• Gruppo Grotte Giara Modon of Valstagna
  Letter of support

• Gruppo Grote Milano – CAI-SEM
  Letter of support

• Gruppo Triestino Speleologi APS (GTS APS)
  Letter of support

• Riserva Naturale “Grotta di Entella” – CAI Sicilia
  Letter of support

• Nature Reserve “Grotta di Santa Ninfa”
  Letter of support

• Club Alpino Italiano Sicilia R.N.I. Monte Conca
  Letter of support

• Speleo Club Ibleo (SCI)
  Letter of support

• Federazione Speleologica Regionale dell’Emilia-Romagna (FSRER)
  Letter of support

• Gruppi Ricerca Ecologica Sicilia
  Letter of support

• La Venta Geographic Exploration Association APS
  Letter of support

Mexico

• Karst Lab México
  Letter of support

Philippines

• National Cave Committee, Biodiversity Management Bureau
  Letter of support

Portugal

• UNESCO Chair in Geodiversity and Geoconservation (in partnership between universities in Australia, Botswana, Brazil, Cameroon, Chile, Colombia, Morocco, Mozambique, Portugal and Uruguay)
  Letter of support

• Portuguese Geological Survey
  Letter of support

Romania

• Institutul de Speologie "Emil Racovita" al Academiei Române Calea
  Letter of support

• Emil G. Racoviță Foundation for Science and Exploration of Extreme Environments
  Letter of support

Serbia

• University of Belgrade/Faculty of Biology
  Letter of support

Slovenia

• Slovenian Academy of Science and Arts (SAZU)
  Letter of support

• Park Škocjan Caves, UNESCO WHS
  Letter of support

• Karst Research Institute ZRC SAZU
  Letter of support

• UNESCO Karst Education, Chair
  Letter of support

• University of Ljubljana, Biotechnical Faculty
  Letter of support

• Geological Survey of Slovenia (GeoZS)
  Letter of support

• Institute of the RS for Nature Conservation
  Letter of support

• Association of Slovenian Geographers (ZSG)
  Letter of support

• Slovenian Geological Society (SGS)
  Letter of support

• Geomorphological Society of Slovenia (GMDS)
  Letter of support

• Society Dinaricum
  Letter of support

• Postojnska Jama (Postojna Cave) d.d.
  Letter of support

Spain

• Institut Català d’Espeleologia i Ciències del Karst (ICEK)
  Letter of support

• Nerja Cave Research Institute
  Letter of support

USA

• United States Biosphere Network (USBN)
  Letter of support

• Mammoth Cave Biosphere Region (MCBR)
  Letter of support

• Florida Geological Survey, Environmental Protection
  Letter of support

PUERTO RICO

• Gruta Troglodita Norman Veve
  Letter of support

• Ciudadanos del Karso
  letter of support

Venezuela

• Theraphosa Asociación Cultural Y Explorativa
  Letter of support

Zimbabwe

• University of Zimbabwe, Research, Innovation and Industrialisation
  Letter of support