# Document-Person Expansion Overview (Version 4)

Version 4 defines the relationship-model evolution track for linking `Document` and `Person` entities with extensible roles, suggestion review, and policy enforcement.

## Start Here

Read [scope_boundary_v4.md](scope_boundary_v4.md) first to confirm scope and non-scope before implementation work begins.

## Core V4 Capabilities

- Extensible relationship role taxonomy.
- Many-people-per-role linking for documents.
- Explicit distinction between canonical asserted links and pending suggested links.
- Human-in-the-loop suggestion accept/reject workflow.
- Role exclusivity policy enforcement for configured role pairs.
- Role/state-aware API and UI retrieval/presentation behavior.
- Minimal document type governance rollout for the current corpus, with one-time manual mapping and no alias helper table.

## V4 Documentation Index

- [Scope Boundary](scope_boundary_v4.md)
- [System Requirements](requirements_v4.md)
- [Data Model](schema_v4.md)
- [System Architecture](architecture_v4.md)
- [Error Handling Policy](error_handling_v4.md)
- [Implementation Plan](implementation_plan_v4.md)

## Relationship To V3

V3 remains the baseline production architecture and requirements set for transcription pipeline behavior. V4 is an additive evolution track focused on document-person relationship semantics and workflows.

## Decision Status

Locked decisions:

1. Role extensibility uses registry tables.
2. Suggestion storage uses a separate suggestion table.
3. Exclusivity baseline is `author` vs `recipient` exclusive, with `mentioned` non-exclusive.
4. API evolution is additive in development mode with explicit deprecate-then-remove behavior.

Remaining decision:

1. Suggestion generation strategy (deterministic rules/NLP vs LLM extraction).

## Related Local References

- [V3 System Overview](../index_v3.md)
- [V3 Requirements](../requirements_v3.md)
- [V3 Schema](../schema_v3.md)