diff --git a/docs/GLOSSARY.md b/docs/GLOSSARY.md
index 99da1775..1fefb7af 100644
--- a/docs/GLOSSARY.md
+++ b/docs/GLOSSARY.md
@@ -25,6 +25,11 @@ _Not to be confused with [AppUser](#appuser-appuser)_ — `Person` is a historic
 
 **UserGroup** (`UserGroup`) — a named permission bundle assigned to one or more `AppUser`s. A user's effective permissions are the union of all permissions across all groups they belong to.
 
+**source_ref** (`Person.sourceRef`, `Tag.sourceRef`) — the import normalizer's stable identity for a `Person` (its `person_id`) or `Tag` (its canonical `tag_path`). It is the join key linking normalized records to documents and the idempotency key for re-import; null for manually created records and unique among non-null values.
+
+**provisional person** (`Person.provisional`) — a `Person` the importer inferred from raw attribution text but could not confidently match to a known individual. The flag lets the persons directory surface uncertainty honestly rather than fabricate a confident identity; it defaults to `false` and is set `true` only by the importer.
+_Not to be confused with `family_member`_ — `provisional` expresses import confidence, while `family_member` is a genealogical fact about whether the person belongs to the family tree.
+
 ---
 
 ## Document-Related Terms
@@ -36,6 +41,10 @@ _See also [TranscriptionBlock](#transcriptionblock-transcriptionblock)._
 
 **Document** (`Document`) — a single archival item (letter, postcard, photograph) with a file stored in MinIO/S3 and associated metadata (sender, receivers, date, tags, transcription blocks).
 
+**date precision** (`Document.metaDatePrecision`, enum `DatePrecision`) — how exactly a document's date is known, one of `DAY, MONTH, SEASON, YEAR, RANGE, APPROX, UNKNOWN`. A verbatim mirror of the import normalizer's `Precision` enum so honest dates can be rendered (`APPROX` → "ca.", `RANGE` uses `meta_date_end`) instead of fabricating a false `DAY`-level date. `UNKNOWN` is the explicit value for undated documents.
+
+**raw attribution** (`Document.senderText`, `Document.receiverText`, `Document.metaDateRaw`) — the original spreadsheet cell text for a document's sender, receiver, and date, preserved verbatim even after a `Person` or normalized date is linked. It keeps provenance intact and enables an "as written in the original" view.
+
 **DocumentVersion** (`DocumentVersion`) — an append-only snapshot of a `Document`'s metadata at a point in time. Append-only by convention; no consumer-facing create or update endpoint exists. The entity uses Lombok `@Data` (which generates setters), so immutability is enforced by application convention, not at the Java level.
 
 **Tag** (`Tag`) — a hierarchical category that can be applied to `Document`s. Tags are self-referencing via a `parent_id` foreign key, forming a tree structure.
diff --git a/docs/adr/025-canonical-import-and-single-migration-schema-foundation.md b/docs/adr/025-canonical-import-and-single-migration-schema-foundation.md
new file mode 100644
index 00000000..0feb670b
--- /dev/null
+++ b/docs/adr/025-canonical-import-and-single-migration-schema-foundation.md
@@ -0,0 +1,83 @@
+# ADR-025 — Canonical Import Output as Contract & Single-Migration Schema Foundation
+
+**Date:** 2026-05-27
+**Status:** Accepted
+**Issue:** #671
+**Milestone:** Handling the Unknowns — honest uncertainty in dates & people
+
+---
+
+## Context
+
+The "Handling the Unknowns" milestone introduces honest uncertainty into the archive:
+documents whose dates are known only approximately or as a range, and people the importer
+infers from raw attribution text but cannot confidently identify. Three sibling issues —
+date precision (#666), name triage (#665), and the importer (#669) — each independently
+planned a Flyway `V69` migration that altered `persons`. Three `V69`s is a boot failure
+(Flyway versions must be unique), and `persons.provisional` was at risk of being defined
+twice.
+
+Two durable decisions had to be made before any application code in Phases 3–6 could
+compile against the new schema.
+
+---
+
+## Decision
+
+### 1. All import/precision/attribution/identity schema lives in ONE migration with a single owner
+
+`V69__import_precision_attribution_identity_schema.sql` adds every new column for this
+milestone in a single, atomic, forward-only migration:
+
+- `documents`: `meta_date_precision` (backfilled `DAY` where dated / `UNKNOWN` where not,
+  then `NOT NULL`), `meta_date_end`, `meta_date_raw`, `sender_text`, `receiver_text`.
+- `persons`: `source_ref` (unique index, nullable), `provisional` (`NOT NULL DEFAULT false`).
+- `tag`: `source_ref` (unique index, nullable).
+
+Integrity is pushed to the database as fail-closed `CHECK` constraints (the precedent is
+`V22`'s `person_type` allowlist):
+
+- `meta_date_precision` must be one of the seven enum values.
+- `meta_date_end` may be non-null **only** when precision = `RANGE` (one-directional, not
+  biconditional — see Consequences).
+- `meta_date_end >= meta_date` for ranges with both endpoints (a `CHECK`, not a trigger).
+- `meta_date_raw`, `sender_text`, `receiver_text` are length-capped at 10 000 (mirrors the
+  `transcription_blocks` cap in `V18`).
+
+No sibling issue adds another migration that alters `persons` or `documents` in this
+milestone.
+
+### 2. The backend `DatePrecision` enum is a verbatim mirror of the normalizer's `Precision`; the canonical output is the contract
+
+The importer reads the Python normalizer's canonical output
+(`tools/import-normalizer/`). The backend `DatePrecision` enum
+(`DAY, MONTH, SEASON, YEAR, RANGE, APPROX, UNKNOWN`) is a verbatim copy of the normalizer's
+`Precision(StrEnum)` (`dates.py`). There is **no translation layer**: the normalizer's
+output strings are persisted as-is. The same applies to `source_ref`, which carries the
+normalizer's `person_id` / canonical `tag_path` unchanged as the re-import idempotency key.
+
+---
+
+## Consequences
+
+- **RANGE is one-directional, not biconditional.** A `RANGE` row may have a null
+  `meta_date_end` (an open-ended range with only a start), because the normalizer can emit
+  start-only ranges. A biconditional `RANGE ⟺ end IS NOT NULL` rule would reject valid
+  normalizer output, so it was rejected. Phase 4 rendering must handle a `RANGE` with no end
+  gracefully.
+- **`provisional` stays `false` throughout this phase.** The column and flag exist, but no
+  code path sets it `true`; the importer (Phase 3) is the only writer. This is intentional,
+  not a half-built feature.
+- **A future dev must not "improve" the enum.** Renaming or dropping a `DatePrecision` value
+  without changing the normalizer silently breaks import idempotency and date rendering. The
+  enum's Javadoc states this; the DB `CHECK` enforces validity independent of the Java enum.
+- **`source_ref` is unique + nullable.** Manually created persons/tags have `source_ref =
+  NULL`; Postgres allows multiple NULLs under a plain unique index, so no backfill is needed.
+- **Forward-only.** The migration is immutable once shipped (Flyway checksum model); any fix
+  goes in a later version. There is no down-migration — rollback means restoring from the
+  nightly `pg_dump`, the standard procedure.
+- **`PersonSummaryDTO` coupling.** `provisional` was added to the `PersonSummaryDTO` native
+  interface projection; because the projection is backed by native SQL, the column had to be
+  added to all three native `SELECT`s (`findAllWithDocumentCount`, `searchWithDocumentCount`,
+  `findTopByDocumentCount`) or it would silently return `false`. Guarded by integration tests
+  against real Postgres.
diff --git a/docs/architecture/db/db-orm.puml b/docs/architecture/db/db-orm.puml
index a6e64aa3..7b03c156 100644
--- a/docs/architecture/db/db-orm.puml
+++ b/docs/architecture/db/db-orm.puml
@@ -1,6 +1,6 @@
 @startuml db-orm
-' Schema source: Flyway V1–V60 (excl. V37, V43 — intentionally removed)
-' Schema as of:  V60 (2026-05-06)
+' Schema source: Flyway V1–V69 (excl. V37, V43 — intentionally removed)
+' Schema as of:  V69 (2026-05-27)
 ' ⚠ This is a versioned snapshot. Update when the schema changes significantly.
 
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@@ -88,6 +88,11 @@ package "Documents" {
     summary : TEXT
     transcription : TEXT
     meta_date : DATE
+    meta_date_precision : VARCHAR(16) NOT NULL
+    meta_date_end : DATE
+    meta_date_raw : TEXT
+    sender_text : TEXT
+    receiver_text : TEXT
     meta_location : VARCHAR(255)
     meta_document_location : VARCHAR(255)
     archive_box : VARCHAR(255)
@@ -182,6 +187,8 @@ package "Persons" {
     birth_year : INTEGER
     death_year : INTEGER
     family_member : BOOLEAN NOT NULL
+    source_ref : VARCHAR(255) UNIQUE
+    provisional : BOOLEAN NOT NULL
   }
 
   entity person_name_aliases {
@@ -217,6 +224,7 @@ package "Tags" {
     name : VARCHAR(255) NOT NULL UNIQUE
     parent_id : UUID <<FK>>
     color : VARCHAR(20)
+    source_ref : VARCHAR(255) UNIQUE
   }
 }
 
diff --git a/docs/architecture/db/db-relationships.puml b/docs/architecture/db/db-relationships.puml
index c3100cfa..d6f4b542 100644
--- a/docs/architecture/db/db-relationships.puml
+++ b/docs/architecture/db/db-relationships.puml
@@ -1,7 +1,9 @@
 @startuml db-relationships
-' Schema source: Flyway V1–V60 (excl. V37, V43 — intentionally removed)
-' Schema as of:  V60 (2026-05-06)
+' Schema source: Flyway V1–V69 (excl. V37, V43 — intentionally removed)
+' Schema as of:  V69 (2026-05-27)
 ' ⚠ This is a versioned snapshot. Update when the schema changes significantly.
+' Note: V69 adds columns only (persons.source_ref, tag.source_ref, document
+' precision/attribution fields); no new FK relationships, so this diagram is unchanged.
 
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