# Defensive publication

> Defensive publication is publicly disclosing a plant, trait or method so it becomes prior art, preventing others from later patenting it as new.

- Canonical: https://genetixbay.com/knowledge/glossary/defensive-publication.html
- Also written: defensive disclosure, prior art publication, publish to protect, defensive publishing
- Glossary category: Legal and regulatory
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

Defensive publication means deliberately making an invention, variety or trait public, with enough detail and a reliable date, so that it counts as prior art. Patent offices cannot validly grant a patent on something already publicly disclosed, so publication keeps it in the public domain.

## In practice

For cannabis, a defensive publication might be a dated, public record of a line's lineage, [photos](https://genetixbay.com/knowledge/glossary/photoperiod.md), growth habit and lab-measured [chemotype](https://genetixbay.com/knowledge/glossary/chemotype.md), or a written description of a breeding or processing technique. To work, the record must be accessible, dated in a way that can be proven, and specific enough that a skilled person could recognise or reproduce it.

GenetixBay's public [GB-ID](https://genetixbay.com/knowledge/glossary/gb-id.md) records, dated journals and open trial results can serve this role as a side effect of good documentation. Whether a specific record defeats a specific patent claim is a legal question for patent professionals.

Rules differ by country, state, province and city, and change often. This is a general definition, not legal advice: check local rules.

## Don't confuse with

- **Open-source seed pledge**: a promise about how seed may be used, not a disclosure for prior art.
- **Trade secret**: the opposite strategy, keeping it private.

## Related terms

[Utility patent](https://genetixbay.com/knowledge/glossary/utility-patent.md), [Open-source seed](https://genetixbay.com/knowledge/glossary/open-source-seed.md), [GB-ID](https://genetixbay.com/knowledge/glossary/gb-id.md), [Open research](https://genetixbay.com/knowledge/glossary/open-research.md)

## Read more

- [Patents and the gene pool: who can own a cannabis plant?](https://genetixbay.com/knowledge/genetics-history/patents-and-the-gene-pool.md)
- [How to document lineage evidence (GB-ID evidence levels L0-L4)](https://genetixbay.com/knowledge/breeding/documenting-lineage-evidence.md)

## Sources

1. Kloppenburg J. 2014. Re-purposing the master's tools: the open source seed initiative and the struggle for seed sovereignty. Journal of Peasant Studies 41(6):1225-1246. https://doi.org/10.1080/03066150.2013.875897