# Blog: Data

> Data fields, access tiers and evidence of the battery passport in detail.

Data fields, access tiers and evidence of the battery passport in detail.

- [DataProvenance and four-eyes review: why who entered what mattersWhat the Battery Regulation requires of accurate, untampered passport data, and how per-value provenance, four-eyes approval and signed versions prove it.25 October 2026](https://kabin.sh/en/blog/provenance-and-four-eyes-review-battery-passport)