> For the complete documentation index, see [llms.txt](https://dev.guardian.hedera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev.guardian.hedera.com/guardian/readme/discovering-esg-assets-on-hedera.md).

# Discovering Environmental assets on Hedera

As identified in Hedera Improvement Proposal 19 (HIP-19), each entity on the Hedera network may contain a specific identifier in the memo field for discoverability. Guardian demonstrates this when every Hedera Consensus Service transaction is logged to a Hedera Consensus Service Topic. Observing the Hedera Consensus Service Topic, you can discover newly minted tokens. In the memo field of each token mint transaction you will find a unique Hedera message timestamp. This message contains the url of the Verifiable Presentation (VP) associated with the token. The VP can serve as a starting point from which you can traverse the entire sequence of documents produced by Guardian policy workflow, which led to the creation of the token. Please see p.17 in the [FAQ](https://docs.hedera.com/guardian/faqs/) for more information. This is further defined in [Hedera Improvement Proposal 28 (HIP-28)](https://hips.hedera.com/hip/hip-28).