diff --git a/.repo-classification.yaml b/.repo-classification.yaml
new file mode 100644
index 0000000..0af4e2f
--- /dev/null
+++ b/.repo-classification.yaml
@@ -0,0 +1,38 @@
+repo_classification:
+  standard: Repo Classification Standard
+  version: "1.0"
+  classified_at: "2026-06-22"
+  classified_by: agent
+
+  # the-custodian is the governance/continuity substrate: canon, standards,
+  # ADRs, charters, memory, and cross-domain coordination scaffolding.
+  category: research
+  domain: infotech
+  secondary_domains:
+    - agents
+
+  capability_tags:
+    - governance
+    - knowledge
+    - coordination
+    - policy
+    - documentation
+
+  business_stake:
+    - technology
+    - operations
+    - intelligence
+    - execution
+
+  business_mechanics:
+    - intention
+    - control
+    - coordination
+    - adaptation
+
+  notes: >
+    Primary domain is infotech (the intended users are the ecosystem's
+    developers and agents); agents is a secondary domain because the repo is
+    agent-coordination infrastructure. Classified as research because its core
+    output is canon, standards, and decision records rather than a deployable
+    product. First-pass agent classification pending human review (CUST-WP-0050 T02).
diff --git a/canon/standards/repo-classification-standard_v1.0.md b/canon/standards/repo-classification-standard_v1.0.md
index 2558696..2c5f68b 100755
--- a/canon/standards/repo-classification-standard_v1.0.md
+++ b/canon/standards/repo-classification-standard_v1.0.md
@@ -682,6 +682,10 @@ Add only the mechanics that materially apply.
 
 ## 12. Validation Checklist
 
+The controlled vocabularies are maintained in machine-readable form at
+`canon/standards/repo-classification.allowed.yaml`. Validate a file with
+`tools/validate_repo_classification.py <path-to-.repo-classification.yaml>`.
+
 A repo classification is valid when:
 
 - [ ] `category` exists and has exactly one allowed value.
diff --git a/canon/standards/repo-classification.allowed.yaml b/canon/standards/repo-classification.allowed.yaml
new file mode 100644
index 0000000..5341b9e
--- /dev/null
+++ b/canon/standards/repo-classification.allowed.yaml
@@ -0,0 +1,111 @@
+# Machine-readable allowed-values for the Repo Classification Standard.
+#
+# Single source of truth for the standard's controlled vocabularies, derived
+# from canon/standards/repo-classification-standard_v1.0.md. Consumed by:
+#   - the per-repo .repo-classification.yaml linter (tools/validate_repo_classification.py)
+#   - the State Hub registration validator (CUST-WP-0050 T04)
+#
+# When the standard's vocabularies change, update this file and bump `version`
+# to match the standard version. CUST-WP-0050 T01.
+
+standard: "Repo Classification Standard"
+version: "1.0"
+canon_id: "canon-repo-classification"
+
+# category — exactly 1 required (§5)
+categories:
+  - experimental
+  - research
+  - project
+  - product
+  - business
+
+# domain / secondary_domains — primary exactly 1; secondaries 0..n (§6)
+domains:
+  - infotech
+  - financials
+  - communication
+  - consumer
+  - health
+  - industrials
+  - energy
+  - utilities
+  - materials
+  - realestate
+  - crypto
+  - agents
+  - space
+  - government
+
+# business_stake — 0..n; 2..6 recommended (§8)
+business_stake:
+  - execution
+  - intelligence
+  - finance
+  - legal
+  - sales
+  - experience
+  - technology
+  - operations
+  - product
+  - people
+  - procurement
+  - sustainability
+  - automation
+
+# business_mechanics — 0..n, optional (§9)
+business_mechanics:
+  - intention
+  - control
+  - coordination
+  - operation
+  - adaptation
+
+# capability_tags are intentionally OPEN-ENDED (§7): lowercase kebab-case, not
+# restricted to this set. The families below are the standard's recommended
+# canonical tags — used to warn on likely synonyms/typos, never to reject.
+capability_families:
+  identity_and_access:
+    - identity
+    - authentication
+    - authorization
+    - access-control
+    - user-management
+    - tenancy
+  knowledge_and_evidence:
+    - knowledge
+    - citations
+    - evidence
+    - source-management
+    - traceability
+    - documentation
+  platform_and_operations:
+    - platform
+    - deployment
+    - operations
+    - observability
+    - feature-control
+    - configuration
+    - orchestration
+  market_and_coordination:
+    - marketplace
+    - pricing
+    - reputation
+    - challenges
+    - bounties
+    - collaboration
+    - coordination
+  governance_and_control:
+    - governance
+    - policy
+    - compliance
+    - risk
+    - audit
+    - control
+
+# Validation guidance (advisory bounds the linter applies as warnings)
+guidance:
+  secondary_domains_max: 3
+  business_stake_recommended_min: 2
+  business_stake_recommended_max: 6
+  capability_tag_pattern: "^[a-z0-9]+(-[a-z0-9]+)*$"
diff --git a/tools/validate_repo_classification.py b/tools/validate_repo_classification.py
new file mode 100644
index 0000000..cbf6118
--- /dev/null
+++ b/tools/validate_repo_classification.py
@@ -0,0 +1,186 @@
+#!/usr/bin/env python3
+"""Validate a .repo-classification.yaml against the Repo Classification Standard.
+
+Single small linter shared by repo authors and (later) the State Hub registration
+validator. It checks a repo's classification file against the controlled
+vocabularies in canon/standards/repo-classification.allowed.yaml.
+
+Usage:
+    validate_repo_classification.py <path-to-.repo-classification.yaml> ...
+    validate_repo_classification.py --self-test
+
+Exit code 0 = all files valid (warnings allowed); 1 = at least one invalid.
+
+CUST-WP-0050 T01. Depends on PyYAML (stdlib + pyyaml only).
+"""
+from __future__ import annotations
+
+import re
+import sys
+from pathlib import Path
+
+import yaml
+
+ALLOWED_PATH = (
+    Path(__file__).resolve().parent.parent
+    / "canon"
+    / "standards"
+    / "repo-classification.allowed.yaml"
+)
+
+
+def load_allowed(path: Path = ALLOWED_PATH) -> dict:
+    with path.open() as fh:
+        return yaml.safe_load(fh)
+
+
+def _known_capability_tags(allowed: dict) -> set[str]:
+    tags: set[str] = set()
+    for fam in (allowed.get("capability_families") or {}).values():
+        tags.update(fam or [])
+    return tags
+
+
+def validate(doc: dict, allowed: dict) -> tuple[list[str], list[str]]:
+    """Return (errors, warnings) for a parsed classification document."""
+    errors: list[str] = []
+    warnings: list[str] = []
+
+    block = doc.get("repo_classification") if isinstance(doc, dict) else None
+    if not isinstance(block, dict):
+        return (["missing top-level `repo_classification:` mapping"], [])
+
+    categories = set(allowed["categories"])
+    domains = set(allowed["domains"])
+    stakes = set(allowed["business_stake"])
+    mechanics = set(allowed["business_mechanics"])
+    guidance = allowed.get("guidance", {})
+    pattern = re.compile(guidance.get("capability_tag_pattern", r"^[a-z0-9]+(-[a-z0-9]+)*$"))
+
+    # category — required, exactly one allowed value
+    category = block.get("category")
+    if category is None:
+        errors.append("`category` is required")
+    elif category not in categories:
+        errors.append(f"`category` '{category}' not in {sorted(categories)}")
+
+    # domain — required, exactly one allowed value
+    domain = block.get("domain")
+    if domain is None:
+        errors.append("`domain` is required")
+    elif domain not in domains:
+        errors.append(f"`domain` '{domain}' not in allowed domains")
+
+    # secondary_domains — 0..n allowed domains, excluding primary, no dups
+    secondary = block.get("secondary_domains") or []
+    if not isinstance(secondary, list):
+        errors.append("`secondary_domains` must be a list")
+        secondary = []
+    for d in secondary:
+        if d not in domains:
+            errors.append(f"secondary domain '{d}' not in allowed domains")
+        if d == domain:
+            errors.append(f"secondary domain '{d}' repeats the primary domain")
+    if len(secondary) != len(set(secondary)):
+        errors.append("`secondary_domains` contains duplicates")
+    smax = guidance.get("secondary_domains_max", 3)
+    if len(secondary) > smax:
+        warnings.append(f"{len(secondary)} secondary_domains exceeds recommended max {smax}")
+
+    # capability_tags — open-ended, kebab-case; warn on unknown/synonym
+    tags = block.get("capability_tags") or []
+    if not isinstance(tags, list):
+        errors.append("`capability_tags` must be a list")
+        tags = []
+    known = _known_capability_tags(allowed)
+    for t in tags:
+        if not isinstance(t, str) or not pattern.match(t):
+            errors.append(f"capability_tag '{t}' is not lowercase kebab-case")
+        elif t not in known:
+            warnings.append(f"capability_tag '{t}' is not a recommended family tag (allowed, check for synonym)")
+
+    # business_stake — 0..n allowed; recommend 2..6
+    stake = block.get("business_stake") or []
+    if not isinstance(stake, list):
+        errors.append("`business_stake` must be a list")
+        stake = []
+    for s in stake:
+        if s not in stakes:
+            errors.append(f"business_stake '{s}' not in {sorted(stakes)}")
+    if stake:
+        lo = guidance.get("business_stake_recommended_min", 2)
+        hi = guidance.get("business_stake_recommended_max", 6)
+        if not (lo <= len(stake) <= hi):
+            warnings.append(f"{len(stake)} business_stake values; {lo}-{hi} recommended")
+
+    # business_mechanics — 0..n allowed
+    mech = block.get("business_mechanics") or []
+    if not isinstance(mech, list):
+        errors.append("`business_mechanics` must be a list")
+        mech = []
+    for m in mech:
+        if m not in mechanics:
+            errors.append(f"business_mechanics '{m}' not in {sorted(mechanics)}")
+
+    return errors, warnings
+
+
+def validate_file(path: Path, allowed: dict) -> bool:
+    try:
+        doc = yaml.safe_load(path.read_text())
+    except (OSError, yaml.YAMLError) as exc:
+        print(f"FAIL  {path}: cannot read/parse ({exc})")
+        return False
+    errors, warnings = validate(doc, allowed)
+    for w in warnings:
+        print(f"warn  {path}: {w}")
+    if errors:
+        for e in errors:
+            print(f"FAIL  {path}: {e}")
+        return False
+    print(f"ok    {path}")
+    return True
+
+
+def self_test(allowed: dict) -> bool:
+    good = {
+        "repo_classification": {
+            "category": "research",
+            "domain": "infotech",
+            "secondary_domains": ["agents"],
+            "capability_tags": ["governance", "knowledge", "coordination"],
+            "business_stake": ["technology", "operations", "intelligence"],
+            "business_mechanics": ["intention", "control", "coordination"],
+        }
+    }
+    bad = {
+        "repo_classification": {
+            "category": "platform",          # not a category (it's a tag)
+            "domain": "knowledge",           # not a market domain
+            "secondary_domains": ["infotech", "infotech"],
+            "capability_tags": ["Stuff", "access-control"],
+            "business_stake": ["technology", "wizardry"],
+            "business_mechanics": ["teleportation"],
+        }
+    }
+    ge, _ = validate(good, allowed)
+    be, _ = validate(bad, allowed)
+    ok = (ge == []) and (len(be) >= 5)
+    print(f"self-test: good_errors={len(ge)} bad_errors={len(be)} -> {'PASS' if ok else 'FAIL'}")
+    return ok
+
+
+def main(argv: list[str]) -> int:
+    allowed = load_allowed()
+    args = argv[1:]
+    if not args or args == ["--self-test"]:
+        return 0 if self_test(allowed) else 1
+    all_ok = True
+    for a in args:
+        if not validate_file(Path(a), allowed):
+            all_ok = False
+    return 0 if all_ok else 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main(sys.argv))
diff --git a/workplans/CUST-WP-0050-repo-classification-registration-redesign.md b/workplans/CUST-WP-0050-repo-classification-registration-redesign.md
index 7e661d0..ea2fbf6 100644
--- a/workplans/CUST-WP-0050-repo-classification-registration-redesign.md
+++ b/workplans/CUST-WP-0050-repo-classification-registration-redesign.md
@@ -4,13 +4,14 @@ type: workplan
 title: "Repo Classification & State Hub Registration Redesign"
 domain: custodian
 repo: the-custodian
-status: proposed
+status: active
 owner: custodian
 topic_slug: custodian
 planning_priority: high
 planning_order: 50
 created: "2026-06-22"
 updated: "2026-06-22"
+started: "2026-06-22"
 state_hub_workstream_id: "9f031f48-8de8-48b6-8e69-d2d83ad70a7a"
 ---
 
@@ -150,7 +151,7 @@ hub remains a read/index model fed by repo-owned files (ADR-001).
 
 ```task
 id: CUST-WP-0050-T01
-status: todo
+status: done
 priority: high
 state_hub_task_id: "d978b1f3-4eca-4a17-835b-2c25d13cae22"
 ```
@@ -164,13 +165,20 @@ families) into a single machine-readable artefact (e.g.
 Done when a single allowed-values file exists, is referenced by the standard, and
 a small validator can check a `.repo-classification.yaml` against it.
 
+**Delivered (2026-06-22):** `canon/standards/repo-classification.allowed.yaml`
+(categories, domains, business_stake, business_mechanics, capability families,
+guidance bounds); referenced from the standard §12; validator
+`tools/validate_repo_classification.py` (stdlib + PyYAML) with `--self-test`
+(PASS) — checks category/domain enums, secondary-domain rules, kebab-case tags,
+and stake/mechanics enums.
+
 ### Phase 2 — Classify the portfolio (repo-owned source of truth)
 
 ### T02 - Classify custodian-owned repos
 
 ```task
 id: CUST-WP-0050-T02
-status: todo
+status: in_progress
 priority: high
 state_hub_task_id: "b7edfbb5-483f-4600-9356-8f885c78ce58"
 ```
@@ -183,6 +191,12 @@ standard's §16 agent prompt as a first pass.
 Done when each custodian repo has a committed file that validates against T01 and
 has been reviewed by a human.
 
+**Progress (2026-06-22):** `the-custodian/.repo-classification.yaml` authored
+(category: research · domain: infotech · secondary: agents) and validates clean;
+flagged `classified_by: agent` pending human review. Remaining 10 custodian repos
+(state-hub, hub-core, inter-hub, activity-core, issue-core, kaizen-agentic,
+llm-connect, ops-bridge, ops-warden, email-connect) still to classify.
+
 ### T03 - Classify the full Gitea inventory
 
 ```task