diff --git a/crates/aura-analysis/src/lib.rs b/crates/aura-analysis/src/lib.rs
index 6c4590e..8e6d55b 100644
--- a/crates/aura-analysis/src/lib.rs
+++ b/crates/aura-analysis/src/lib.rs
@@ -236,9 +236,9 @@ pub fn permute<T>(xs: &mut [T], rng: &mut SplitMix64) {
 
 /// Per-metric vocabulary a report payload supplies to the registry's
 /// ranking/deflation machinery (#147). Narrow by design (#136): exactly the
-/// surface the backtest metrics (the sole implementor so far) and the
-/// measurement IC (deflatable today via its own permutation-null path, not
-/// yet through this trait) are expected to share. The registry owns the
+/// surface the two production implementors — the backtest metrics
+/// (`RunMetrics`, centred moving-block null) and the measurement IC
+/// (within-run permutation null) — demonstrably share. The registry owns the
 /// family fold — best-of-K, p95, Laplace, dispersion floor — the payload
 /// owns what each metric IS: its name, direction, value read, and what one
 /// draw of its null statistic means.
@@ -266,9 +266,8 @@ pub trait MetricVocabulary: Sized {
 
 /// One-sided Laplace-smoothed tail estimate `(ge + 1) / (n + 1)`: the
 /// probability mass at-or-above an observed statistic given that `ge` of `n`
-/// null draws reached it. Intended as the single source of the formula the
-/// registry's R deflation arm and the CLI's IC reduction each compute inline
-/// today; wiring those call sites to this function is deferred follow-up.
+/// null draws reached it. The single source of the formula: the registry's
+/// R deflation arm and the CLI's IC reduction both call it.
 pub fn one_sided_p_laplace(ge: usize, n: usize) -> f64 {
     (ge + 1) as f64 / (n + 1) as f64
 }
diff --git a/crates/aura-backtest/src/metrics.rs b/crates/aura-backtest/src/metrics.rs
index d9414f7..1520151 100644
--- a/crates/aura-backtest/src/metrics.rs
+++ b/crates/aura-backtest/src/metrics.rs
@@ -1389,6 +1389,22 @@ mod tests {
         assert_eq!(<RunMetrics as MetricVocabulary>::known(), RANKABLE_METRICS);
         assert!(RunMetricKey::Sqn.r_based());
         assert!(!RunMetricKey::TotalPips.r_based());
+        // Oracle-pin R_BASED_METRICS against the classification itself: the
+        // const feeds the NonRMetric refusal prose, so a divergence would
+        // misreport the R-gate silently rather than fail a lookup.
+        let derived: Vec<&str> = RANKABLE_METRICS
+            .iter()
+            .copied()
+            .filter(|n| {
+                <RunMetrics as MetricVocabulary>::resolve(n)
+                    .expect("roster names resolve")
+                    .r_based()
+            })
+            .collect();
+        assert_eq!(
+            derived, R_BASED_METRICS,
+            "R_BASED_METRICS must be exactly the r_based slice of the roster"
+        );
     }
 
     /// Property: an R-based key on a member with no `r` block ranks worst for
diff --git a/crates/aura-campaign/src/lib.rs b/crates/aura-campaign/src/lib.rs
index b14f511..dda1b4c 100644
--- a/crates/aura-campaign/src/lib.rs
+++ b/crates/aura-campaign/src/lib.rs
@@ -133,10 +133,11 @@ pub enum ExecFault {
 /// `RunMetrics` scalars plus the 11 `RMetrics` scalars. The three
 /// selection-annotation names (`deflated_score` / `overfit_probability` /
 /// `neighbourhood_score`) are deliberately NOT here — they describe a
-/// selection, not a member. Hand-copied roster (the third metric-roster site
-/// beside aura-research's 17-name vocabulary and aura-registry's rankable
-/// set, #190); drift fails safe: an unknown name is a preflight refusal,
-/// never a wrong number.
+/// selection, not a member. Hand-copied roster beside aura-research's 17-name
+/// vocabulary (#190); the rankable set is single-sourced from the backtest
+/// vocabulary since #147, and this roster's nesting is oracle-pinned by the
+/// extended #190 guard. Drift fails safe: an unknown name is a preflight
+/// refusal, never a wrong number.
 pub const PER_MEMBER_METRICS: &[&str] = &[
     "total_pips", "max_drawdown", "bias_sign_flips",
     "expectancy_r", "n_trades", "win_rate", "avg_win_r", "avg_loss_r",
diff --git a/crates/aura-campaign/tests/member_seam_e2e.rs b/crates/aura-campaign/tests/member_seam_e2e.rs
index f5934f0..5362de7 100644
--- a/crates/aura-campaign/tests/member_seam_e2e.rs
+++ b/crates/aura-campaign/tests/member_seam_e2e.rs
@@ -89,8 +89,9 @@ fn member_runner_seam_dispatches_through_dyn_trait_object_and_carries_the_window
 /// Property: every metric name in `RANKABLE_METRICS` (the roster `preflight`
 /// permits a `std::sweep`/`std::walk_forward` stage to SELECT on) is also a
 /// member of `PER_MEMBER_METRICS` and resolves to `Some` via `member_metric`.
-/// The two rosters are independently hand-copied (documented drift risk,
-/// #190); were they to diverge, `preflight` would accept a selection metric
+/// Since #147 the rankable roster is a single-source re-export and the
+/// nesting is guard-pinned; were the rosters still to diverge, `preflight`
+/// would accept a selection metric
 /// that `member_metric` silently reads back as `None` for every member — a
 /// sweep/walk_forward stage that always empties, not a compile error or an
 /// early refusal.
diff --git a/crates/aura-engine/src/lib.rs b/crates/aura-engine/src/lib.rs
index 6828679..0948df6 100644
--- a/crates/aura-engine/src/lib.rs
+++ b/crates/aura-engine/src/lib.rs
@@ -76,9 +76,9 @@ pub use sweep::{
     run_indexed, sweep, GridSpace, ListSpace, ParamRange, RandomSpace, Space, SweepError,
     SweepFamily, SweepPoint,
 };
-// `resample_block`/`MetricStats` are foundation-grade (aura-analysis, #291);
-// re-exported here (unchanged exported name set) so existing
-// `aura_engine::{resample_block, MetricStats}` consumers stay source-compatible.
+// Foundation-grade aura-analysis items, re-exported so ladder rungs without a
+// direct aura-analysis edge (e.g. aura-backtest) reach them through the engine
+// (#291; the metric-vocabulary seam rides the same path, #147).
 pub use aura_analysis::{one_sided_p_laplace, resample_block, MetricStats, MetricVocabulary};
 pub use walkforward::{
     param_stability, walk_forward, RollMode, WalkForwardError, WalkForwardResult,
diff --git a/crates/aura-registry/src/lib.rs b/crates/aura-registry/src/lib.rs
index 2c64f0b..9650404 100644
--- a/crates/aura-registry/src/lib.rs
+++ b/crates/aura-registry/src/lib.rs
@@ -793,8 +793,9 @@ pub struct Generalization {
 }
 
 /// Validate that `metric` is a known, R-based ranking key — the data-free pre-check
-/// the CLI runs before evaluating any instrument. The registry owns metric truth
-/// (C9), so the CLI never duplicates the R-set.
+/// the CLI runs before evaluating any instrument. The R classification lives in the
+/// backtest vocabulary (`RunMetricKey::r_based`, C10); this gate is the registry's
+/// monomorphic wall around it, so the CLI never duplicates the R-set.
 pub fn check_r_metric(metric: &str) -> Result<(), RegistryError> {
     let key = <RunMetrics as MetricVocabulary>::resolve(metric).ok_or_else(|| {
         RegistryError::UnknownMetric {
diff --git a/crates/aura-research/src/lib.rs b/crates/aura-research/src/lib.rs
index 6b47767..34cb060 100644
--- a/crates/aura-research/src/lib.rs
+++ b/crates/aura-research/src/lib.rs
@@ -736,8 +736,9 @@ pub fn content_id_of(canonical: &str) -> String {
 /// (`aura-campaign/tests/metric_vocabulary_e2e.rs`, #190) also enumerates the
 /// shipped scalar fields via serde and goes red on any desync, so a stale
 /// hand-edit here is test-caught rather than silent. Keep this list in sync by
-/// hand when the upstream field sets change (single-sourcing it away waits on
-/// #147).
+/// hand when the upstream field sets change (this list stays a hand-copy by
+/// the crate's ratified core-only isolation; #147 single-sourced the rankable
+/// roster elsewhere and the extended #190 guard pins this list's nesting).
 pub fn metric_vocabulary() -> &'static [&'static str] {
     &[
         "expectancy_r",
diff --git a/docs/design/INDEX.md b/docs/design/INDEX.md
index b38fb9a..69dddb3 100644
--- a/docs/design/INDEX.md
+++ b/docs/design/INDEX.md
@@ -1358,7 +1358,10 @@ in the #136 thread):** the `aura-registry` `Metric` / `metric_cmp` / deflation v
 **stays in the registry by design** — the registry is the trading *selection* layer, not
 the domain-free engine, and its deflation statistics branch irreducibly on metric
 identity (R-bootstrap vs. `total_pips` dispersion floor); forcing genericity would be a
-one-implementor abstraction. **Deferred to the World / C21 layer (explicitly *not* #136):**
+one-implementor abstraction. *(Superseded 2026-07-20: measurement's IC became the second
+implementor — #290 — and the vocabulary moved behind the `MetricVocabulary` trait
+supplied by the outer rungs; see the C28 #147 disposition.)* **Deferred to the World /
+C21 layer (explicitly *not* #136):**
 making `RunReport` generic over a metric type and turning the orchestration/registry layer
 into a reusable domain-agnostic substrate — until then `RunReport` / `RunManifest` /
 `summarize` stay trace-coupled in the engine.
@@ -2677,16 +2680,25 @@ cleanly by layer, so the layering is realized only partially:
   `M = RunMetrics` (`aura-backtest → aura-engine`, an outer→inner edge). The
   ladder direction is enforced for the engine/backtest/analysis rungs by the
   structural test (`c28_layering`, seven-row table).
-- **#147 split, partially retired (user-ratified 2026-07-20).** Item 1 — the
-  metric genericity `RunReport<M>` — shipped as phase 2 above (#292). Item 2 —
-  abstracting the registry `Metric`/`metric_cmp`/deflation vocabulary — stays
-  deferred: the registry sits in the process column, whose trading-awareness
-  this contract permits (`aura-registry → aura-research`, column-internal and
-  legal), and the tree still holds exactly one metric consumer — a measurement
-  run reports tap names, not metrics. It lifts when measurement supplies its
-  first deflatable metric (a tap-to-scalar reduction carrying its own null
-  model, #290); the original one-implementor rationale (#136, user-ratified
-  2026-06-27) holds until then. See #147 for the full disposition.
+- **#147 retired (user-ratified direction 2026-07-20; shipped the same day).**
+  Item 1 — the metric genericity `RunReport<M>` — shipped as phase 2 above
+  (#292). Item 2 — the registry deflation vocabulary — shipped as the ratified
+  "A1" cut, its deferral trigger having fired when measurement supplied its
+  first deflatable metric (the IC, #290): the deliberately narrow
+  `MetricVocabulary` trait (resolve/roster/direction/value/one null draw)
+  lives in `aura-analysis`, re-exported through `aura-engine`; the R
+  vocabulary (`RunMetricKey`, `r_based`, the rosters, the centred
+  moving-block `null_draw`) is supplied by `aura-backtest`; the registry's
+  rank/optimize/deflate machinery is generic over `M: MetricVocabulary` with
+  refusal prose derived from the carried roster; the IC (`aura-cli`) is the
+  second production implementor, bringing its within-run permutation null.
+  The C10 wall stays monomorphic (`check_r_metric`/`generalization` accept
+  only the R vocabulary; `r_based` is the enforcement point). Explicitly
+  still deferred ("A2"): measurement runs as sweep-family citizens (report
+  unification, campaign engine generic-over-M) — until a concrete
+  family/campaign demand exists. The #136 one-implementor rationale is
+  superseded by the second implementor; the registry's process-column
+  trading-awareness holds unchanged. See #147 for the full disposition.
 - The `aura-std` four-layer roster is now cut by layer (phase 4, #288): `aura-std`
   holds the engine nodes only (arithmetic/logic/rolling + the generic sinks);
   `aura-market` (`session`, `resample`), `aura-strategy` (`bias`/`stop_rule`/