Each document carries its own history of changes — so a shared record is traceable, and a sync knows what changed, when, and by whom.
Each document carries its own history — what changed, when, by whom.
A document isn't just its current state; it holds a log of its own changes (a ## History / change-log section, or structured updated: + revision entries in frontmatter). This is quiet housekeeping in a single vault, but it becomes essential the moment documents are shared (Federated brains): a sync needs to know what changed and when to send only the delta, to detect conflicts, and to resolve them fairly. When two vaults hold views of the same record, the change-log is what makes a conflict traceable instead of a mystery — you can see whose edit came first and what it touched. Provenance travels with the atom. Pairs with Atomic documents (the unit that has a history) and the ownership rule (the owner's log is authoritative).
Where it lives: foundational to Federated Brains sync/conflict handling (D:/vault/personal/career/2-active/positioning/2026-07-04_federated-brains-research.md).