catalogueoflife.org

Cite the Catalogue of Life (COL) by naming the version you used, its issue date, and its DOI — for the current release that is COL26.9 XR, issued 2026-09-25, DOI 10.48580/dgz9s. Unless otherwise indicated, COL content is offered under the Creative Commons Attribution 4.0 International License (CC BY 4.0), so you may reuse it as long as you give attribution. Note that COL itself states it cannot guarantee accuracy or completeness and that the catalogue is still incomplete and undoubtedly contains errors.

What to include in a citation

A complete citation needs four elements, all of which appear on the COL homepage and its "Cite data" page:

Because COL releases are versioned and dated, always cite the specific release you actually queried. If you downloaded data months ago and a newer release has since appeared, citing the newer DOI would misrepresent your source.

Base release vs. Extended Release (XR)

The version string matters for citation accuracy. COL documents that its data carries "different gradients of quality":

• The base release is verified by taxonomic experts specifically for COL.
• The Extended Release (XR) adds extra data from other sources, marked with the XR icon.

If your work used XR data, say so in the citation — the "XR" suffix signals that some records come from sources beyond the expert-verified base. See COL's release documentation for the details of each release type.

The license and what it allows

Unless otherwise indicated, all content on the site is offered under Creative Commons Attribution 4.0 International (CC BY 4.0). In practice this means:

• You may copy, redistribute, adapt, and build on the data, including commercially.
• You must give appropriate credit, link to the license, and indicate if changes were made.
• You may not imply that COL or its contributing taxonomists endorse your use.

The "unless otherwise indicated" qualifier is important: individual contributing databases or specific records may carry their own terms. Check the source metadata for any dataset you reuse at scale, and consult the "Cite data" page for COL's own citation guidance.

Accuracy limits you should acknowledge

COL's disclaimer is explicit: it "cannot guarantee the accuracy or completeness of the information," the catalogue "is still incomplete and undoubtedly contains errors," and neither COL nor any contributing database is liable for direct or indirect damage arising from use of its services.

For a research or publication context, this suggests two practical habits:

1. State the version and date so readers can reproduce exactly which snapshot you used.
2. Don't treat COL as the final word on a taxon's status — it is an aggregated checklist, and taxonomic opinions change between releases.

A worked example

Suppose you downloaded the Animalia section in September 2026 and used it to build a species list. A citation following the elements above would read:

Catalogue of Life. COL26.9 XR (2026-09-25). DOI: 10.48580/dgz9s. Accessed via catalogueoflife.org. Licensed under CC BY 4.0.

If you modified the data (for example, filtered or reclassified records), add a phrase such as "Data filtered and adapted by the author." That satisfies the CC BY requirement to indicate changes.

Where to confirm the current details

Version numbers, issue dates, and DOIs change with each release, so verify them at the source rather than reusing an old citation:

• Homepage — shows the active version, issue date, and DOI.
• Cite data — COL's own citation guidance.
• Changelog — what changed between releases.
• Metadata and Sources — provenance for the records you used.

The site also provides a COL API, ChecklistBank, and a COL Mobile app for accessing the same data, but the citation and license terms apply regardless of which access route you use.

The Catalogue of Life (COL) publishes its checklist in two layers: a base release that taxonomic experts have verified specifically for COL, and an Extended Release (XR) that adds data from other sources on top of that base. The base release is the expert-checked core; the XR is broader in coverage but mixes in records whose quality comes from elsewhere. You can tell which one you are looking at by the version label — an XR release carries the "XR" marker and an XR icon next to the extra data.

The two releases at a glance

The key mechanism is that COL does not treat all of its content as equally verified. Its own documentation states that the Catalogue "includes information with different gradients of quality." The base release sits at the expert-verified end of that gradient. The Extended Release deliberately reaches beyond it by pulling in records from other sources, and it flags those additions with the XR icon so users can see where the extra coverage comes from.

Why the distinction matters

If you need a record you can attribute to expert taxonomic review, the base release is the safer choice. If you need the widest possible species coverage and can tolerate records that were not verified specifically for COL, the XR release gives you more. The trade-off is coverage versus uniform verification, not "better" versus "worse" — the XR is a superset that carries its provenance with it.

How to check the current active version

COL labels its active version with a release number, an issue date, and a DOI. As of the version shown on the site:

• Active version: Release COL26.9 XR
• Issued: 2026-09-25
• DOI: 10.48580/dgz9s

The "XR" in that label tells you the active release is the Extended Release. The DOI is the citable identifier for that specific version, so if you reference COL in work that needs a stable citation, use the DOI rather than a bare URL.

Where to go next

• Browse or search the data to see records directly.
• Download the release if you need the full dataset.
• Metadata and Sources pages show where content comes from — useful for tracing an XR record back to its contributing source.
• Releases documentation explains the different release types in COL's own words.
• Cite data gives the citation and DOI conventions.

One caveat worth carrying with you: COL states plainly that it "cannot guarantee the accuracy or completeness" of its information and that the catalogue "is still incomplete and undoubtedly contains errors." That applies to both releases, and it is another reason the XR icon matters — it tells you which parts of a record came in through the extended route rather than the expert-verified base.

The Catalogue of Life (COL) offers several ways to reach its data: browse or search the website for individual taxa, download the full dataset, or query it programmatically through the COL API and ChecklistBank. The right entry point depends on whether you need a one-off lookup, a bulk dataset, or an automated pipeline. All of these routes are listed in the site's main menu under Data, Tools, and About.

Start with the website for lookups and orientation

If you only need to check a name or explore a group, the site's own navigation is the fastest route. The menu exposes:

• Browse – navigate the classification tree by kingdom and down through lower ranks.
• Search – look up a specific taxon by name.
• Metadata – background on the data itself.
• Sources – the contributing databases behind the checklist.
• Metrics – counts and coverage figures.
• Changelog – what changed between releases.

These pages are useful before you commit to a download, because they tell you which release you are looking at and where the records come from.

Download the dataset

The Download entry in the menu is the route for bulk data. COL publishes releases on a versioned schedule; the active version shown on the homepage is COL26.9 XR, issued 2026-09-25, with DOI 10.48580/dgz9s. A release identifier and DOI matter if you need to cite or reproduce your analysis later.

Two release types are described on the site:

The site notes that COL includes information "with different gradients of quality," so the XR label is the signal that a record includes material beyond the expert-verified base. If your work requires only expert-verified content, choose the base release; if broader coverage matters more, the XR release is the relevant one.

Use the API and ChecklistBank for programmatic access

For repeated or automated queries, COL points to:

• COL API – programmatic access to COL data.
• ChecklistBank – the platform behind the checklist; the homepage lists ChecklistBank: 316441.
• COL Mobile – an iPhone app, announced in the site's news feed.

The How To page in the menu is the place to check for access instructions, and Glossary explains terminology you will meet in the data. If you are building a pipeline, confirm the release version and DOI you are querying against, since results are tied to a specific release.

Before you rely on the data

Two things are worth reading on the site itself:

• Cite data – guidance on how to credit COL and the underlying sources.
• Disclaimer – COL states it "cannot guarantee the accuracy or completeness of the information" and that the catalogue "is still incomplete and undoubtedly contains errors." Neither COL nor contributing databases accept liability for damage arising from use of the services.

Content is offered under a Creative Commons Attribution 4.0 International License unless otherwise indicated, so attribution is the baseline condition for reuse.

Choosing your route

• One name or a small set of taxa → Browse or Search.
• A full dataset for offline analysis → Download, choosing base or XR according to whether you need expert-verified-only content.
• Automated or repeated queries → COL API or ChecklistBank, with the How To page as your starting reference.
• Mobile lookup → COL Mobile.

In every case, record the release version and DOI you used, and check the Sources and Metadata pages to understand what is actually behind the records you are citing.

The Catalogue of Life (COL) is an authoritative, continuously updated list of the world's species, maintained by hundreds of global taxonomists and recognized as a Global Core Biodata Resource. It is a taxonomic database rather than a general encyclopedia or news site: its purpose is to provide a single, expert-verified classification of species that other databases, researchers, and applications can build on. If you need a citable species checklist, a downloadable dataset, or programmatic access to taxonomic names and classification, COL is designed for that.

What COL contains

COL aggregates species information across the major kingdoms of life. The current active version is COL26.9 XR, issued 2026-09-25, with DOI 10.48580/dgz9s. The homepage reports the following species counts:

Two release types matter when you use the data:

• Base release — verified by taxonomic experts specifically for COL.
• Extended Release (XR) — includes extra data from other sources, marked with the XR icon.

COL states that its information has "different gradients of quality," so which release you use depends on whether you need strictly expert-verified content or broader coverage.

Who maintains it

COL is maintained by hundreds of global taxonomists and is designated a Global Core Biodata Resource. It has published governance and funding information, and it operates as a community project with news and release announcements. This matters for citation and trust: the content is not crowd-sourced anonymously but assembled and checked through a taxonomic expert network.

How to access the data

COL offers several routes depending on your task:

• Browse and Search — explore the classification interactively on the site.
• Download — obtain datasets directly, with a changelog tracking changes across releases.
• COL API — programmatic access for applications and pipelines.
• ChecklistBank — the underlying platform (the homepage references ChecklistBank: 316441).
• COL Mobile — an iPhone app for on-the-go lookup.
• Metadata, Sources, Metrics — documentation on where data comes from and how it performs.
• Tools — including rcol, an R client for the Catalogue of Life.

There are also dedicated pages for How To Access data, Contribute data, Cite data, and Use Cases, plus a glossary and identifier documentation.

What to keep in mind

COL explicitly states it cannot guarantee the accuracy or completeness of its information and notes that it is still incomplete and "undoubtedly contains errors." Neither COL nor its contributing databases accept liability for damage arising from use of its services. Treat it as the best available expert-maintained checklist, not as an infallible authority — and check the release version and DOI when citing.

Content is offered under a Creative Commons Attribution 4.0 International License unless otherwise indicated, so attribution is required when you reuse it.

The Catalogue of Life (COL) is a reasonable backbone for taxonomic reference and data integration, but it is not a guarantee of correctness. COL describes itself as "the most complete authoritative list of the world's species," maintained by hundreds of global taxonomists, and its base release is verified by taxonomic experts specifically for COL. At the same time, COL states plainly that it "cannot guarantee the accuracy or completeness of the information" and that the catalogue "is still incomplete and undoubtedly contains errors." So the practical answer depends on which release you use and what you need it for: treat COL as an authoritative starting point and a strong identifier/classification layer, not as a final arbiter for every name.

What "authoritative" means here

Two things support reliability claims:

• Expert verification. The base release is checked by taxonomic experts specifically for COL, rather than being purely aggregated.
• Institutional standing. COL is designated a Global Core Biodata Resource, and it is citable with a DOI, which matters for reproducibility.

Two things limit it:

• Explicit incompleteness. COL's own disclaimer says the catalogue is incomplete and contains errors, and that neither COL nor contributing databases are liable for damage from use of its services.
• Scale of coverage varies by group. The active version (COL26.9 XR, issued 2026-09-25, DOI 10.48580/dgz9s) lists Animalia at 1,796,900 species, Plantae at 410,832, Fungi at 174,666, and other kingdoms at 75,675. Uneven totals across kingdoms are a signal that coverage and curation effort are not uniform.

Base release vs. Extended Release (XR): the quality gradient

COL documents that it "includes information with different gradients of quality." That is the single most important distinction for judging fitness for purpose.

If your use case requires the highest available curation, prefer base-release content and treat XR-sourced additions as supplementary. If you need maximum coverage and can tolerate mixed provenance, XR is usable — but you should carry the provenance distinction into your own data model rather than flattening it.

Where COL is a good fit

• Taxonomic reference and name resolution. Using COL as the authority list for matching names to accepted classifications.
• Data integration. Joining occurrence, ecological, or collection datasets onto a shared taxonomic backbone, especially when you record which COL version you used.
• Reproducible pipelines. Because releases are versioned and DOI-citable, you can pin a specific release and cite it.

Where you should verify independently

• Any decision with regulatory, conservation, or legal consequence. COL's disclaimer is explicit that accuracy and completeness are not guaranteed.
• Taxa you know are under revision. A catalogue reflects a snapshot; recent taxonomic changes may not be reflected.
• Records coming from XR-only sources. These are not expert-verified for COL in the same way as the base release.
• Downstream claims of "complete." Coverage counts differ substantially by kingdom, so completeness is group-dependent.

How to check data quality and provenance yourself

COL exposes the material you need to make your own judgement:

• Sources — see which databases contribute to a release.
• Metrics — review coverage and counts.
• Data Quality — understand the quality dimensions COL tracks.
• Metadata and Changelog — confirm what changed between releases.
• Releases — identify the exact version and DOI you are relying on.
• ChecklistBank — the underlying infrastructure referenced alongside the release.

A practical workflow: pick a release, record its version and DOI, pull the taxa you need, note whether each record is base or XR, and spot-check a sample against specialist literature for the groups you care about most.

Bottom line

Use COL when you need an authoritative, citable, expert-informed taxonomic backbone and you are prepared to record version, DOI, and provenance. Do not use it as an unquestioned source of truth for high-stakes decisions, and do not assume uniform completeness across taxonomic groups. The honest framing is: reliable enough to build on, not reliable enough to stop checking.