> For the complete documentation index, see [llms.txt](https://docs.zerolabs.green/zerolabs-tokenization-module/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zerolabs.green/zerolabs-tokenization-module/audit-trail.md).

# Audit trail

Zero Labs uses the following flow to make sure that there's a [**bi-directional link**](/zerolabs-tokenization-module/domain-definitions/bi-directional-link.md) between the REC Registry redemption statement and the minted Certificates (NFTs).

### Flow

![REC Registry user tokenizing their RECs (high-level flow)](/files/b9eK3Mq2hOt8UTT18YtI)

### Sequence diagram

![](/files/eLmfmRWuHWwJLZ9I9uiA)