# Evidence levels L0-L4

> GenetixBay evidence levels rate lineage claims from L0 (unverified) through L1 community reported, L2 breeder reported and L3 documented to L4 lab-confirmed.

- Canonical: https://genetixbay.com/knowledge/glossary/evidence-levels-l0-l4.html
- Also written: L0, L1, L2, L3, L4, lineage evidence levels, GB-ID evidence levels
- Glossary category: GenetixBay terms
- 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"

On GenetixBay every parentage statement ("A x B", "the original cut") is treated as a claim with an evidence level. The levels run from L0 to L4.

## In practice

Breeders raise a claim's level by attaching dated, original evidence and, ideally, by recording crosses on the platform as they happen. A certified breeder can still make an L2 claim that turns out wrong, so a verified breeder account is shown separately from verified genetics. Witnessed lineage (both parents on record and the pollination logged at the time) is a separate flag, not a substitute for L4.

## Units and formula

| Level | Name | Typical evidence |
|---|---|---|
| L0 | Unverified | A name or anonymous assertion |
| L1 | Community reported | A member's claim with a source, such as a dated forum post or a [photo](https://genetixbay.com/knowledge/glossary/photoperiod.md) of an old pack |
| L2 | Breeder reported | The line's certified breeder asserts it |
| L3 | Documented | A period document accepted by an archivist: catalogue, patent, [breeders' rights](https://genetixbay.com/knowledge/glossary/plant-variety-protection.md) filing, [lab certificate](https://genetixbay.com/knowledge/glossary/coa.md) ([chemotype](https://genetixbay.com/knowledge/glossary/chemotype.md) only) |
| L4 | Lab-confirmed | A genomic report consistent with the specific parent-child relationship |

## Don't confuse with

- **Evidence ladder**: the Established-to-Myth labels for growing claims in articles.
- **Lab COA**: proves chemistry, not parentage.

## Related terms

[GB-ID](https://genetixbay.com/knowledge/glossary/gb-id.md), [Evidence ladder](https://genetixbay.com/knowledge/glossary/evidence-ladder.md), [Renamed cut](https://genetixbay.com/knowledge/glossary/renamed-cut.md), [Genotyping](https://genetixbay.com/knowledge/glossary/genotyping.md), [Elite cut](https://genetixbay.com/knowledge/glossary/elite-cut.md)

## Read more

- [How to document lineage evidence (GB-ID evidence levels L0-L4)](https://genetixbay.com/knowledge/breeding/documenting-lineage-evidence.md)
- [Genotyping: what a DNA test can and can't prove](https://genetixbay.com/knowledge/breeding/genotyping-what-tests-prove.md)