Key Documents

A range of key IUCN Red List guidance and policy documents are available. These provide guidance on how to prepare high-quality assessments for publication on the IUCN Red List and regional Red Lists, how to use Red List data, and more. 

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Categories and Criteria

The IUCN Red List Categories and Criteria. Version 3.1 were adopted by IUCN Council in February 2000. All new assessments and reassessments on the IUCN Red List must use this systemIn 2012 the second edition of this publication was released.   

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In addition to the IUCN Red List guidance and policy documents referred to above, a number of books and scientific articles related to The IUCN Red List have been produced by IUCN, IUCN SSC Specialist Groups, Red List Partners and others. Lists of these publications are provided with links where possible to the PDF versions:

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Classification Schemes

In order to ensure global uniformity when describing the habitat in which a taxon occurs, the threats to a taxon, what conservation measures are in place or are needed, and whether or not the taxon is utilized, a set of standard terms (Classification Schemes; formerly referred to as Authority Files) have been developed for documenting taxa on the IUCN Red List. 

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Data Organization

The IUCN Red List of Threatened Species is available only as an electronic version on the World Wide Web. The information presented is based on data extracted from the Species Information Service (SIS) database and is maintained by the Red List Unit of the IUCN Global Species Programme. 

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Spatial Data Download

The 2013 IUCN Red List of Threatened Species contains assessments for almost 70,000 species, of which about 43,000 has spatial data. Spatial data are provided to download for most of the comprehensively assessed taxonomic groups such as amphibians, mammals, reef-building corals, seasnakes, sea cucumbers, seagrasses, mangroves and cone snails.

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Information Sources and Quality

The information about each taxon listed on the IUCN Red List often represents an accumulation of knowledge derived from previously published Red Lists, including the 1996 IUCN Red List of Threatened Animals and The World List of Threatened Trees which were the last IUCN Red Lists to be published as hardcopy books. Users are therefore referred to these previous publications when checking on information sources and data quality. 

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Assessment Process

The majority of assessments appearing on the IUCN Red List are carried out by members of the IUCN SSC Specialist Groups appointed Red List Authorities, or by participants of Global Biodiversity Assessment workshops. However, assessments can be done by anyone and submitted to IUCN for consideration. 

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Planned IUCN Red List Updates

Red List assessments are constantly being compiled and submitted for publication on the IUCN Red List of Threatened SpeciesTM, and the underlying database is constantly expanding and changing as new species are brought in and existing species undergo taxonomic revisions. To ensure a regular flow of assessments on to the web site, The IUCN Red List is updated at least twice each year.

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Red List Training

IUCN receives frequent requests from around the world for advice on red listing and for formal training on how to use the IUCN Red List Categories and Criteria. In response to these requests, IUCN has developed new and revitalised training materials to facilitate understanding and application of IUCN Red List methodology.

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The text on many of the static pages on this Red List web site includes citations of various references. This is particularly so on the Data OrganizationSources & Quality pages and Table 1 of the Summary Statistics. The full details of these references are provided here.

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