diff --git a/AGENTS.md b/AGENTS.md
index 64d26c5df..4868ff49b 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -708,6 +708,16 @@ axis share. Rank-0 unused axes still name leftover-axis tick
 `σ 0.00`. Do not invent leftover-map singular values from leftover-map axis share. Do not invent leftover-map
 axis share from leftover-map singular values. This increment does not change leftover-map comparison leftover-axis
 ticks.
+ADR 0331 captions leftover-map comparison graphic leftover-map axis ticks with persisted leftover-map
+axis share when leftoverMapComparePlotTickAxisBadge returns a usable leftover-map axis tick leftover-map
+axis share caption. Distinct accessible names
+`leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%` and
+`leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%`.
+Share and singular value omit independently. Rank-0 unused axes still name leftover-map
+comparison graphic leftover-map axis tick leftover-map axis share `0%`. Do not invent leftover-map
+axis share from leftover-map singular values. Do not invent leftover-map singular values from leftover-map
+axis share. Leftover-map graphic leftover-map axis ticks, leftover-map comparison leftover-axis ticks,
+and leftover-axis ticks never name leftover-map axis share this increment.
 When `R`, `R̂`, `U`, `x`,
 `s`, and `e` are finite, `e + s + x = 1`. When `Y`, `E`, and `R` are
 finite, `Y − E = R`. When `R`, `R̂`, and `U` are
@@ -827,6 +837,16 @@ singular values `σ_k` when leftoverMapPlotTickAxisBadge returns a usable leftov
 Leftover-map comparison graphic leftover-map axis tick leftover-map singular values independently of leftover-map axis share
 (ADR 0328) captions leftover-map comparison graphic leftover-map axis ticks with persisted leftover-map
 singular values `σ_k` when leftoverMapComparePlotTickAxisBadge returns a usable leftover-map axis tick caption.
+Leftover-map comparison leftover-axis tick leftover-map singular values independently of leftover-map axis share
+(ADR 0329) captions leftover-map comparison leftover-axis ticks with persisted leftover-map
+singular values `σ_k` when leftoverMapCompareAxisTickBadge returns a usable leftover-axis tick caption.
+Leftover-axis tick leftover-map singular values independently of leftover-map axis share
+(ADR 0330) captions leftover-axis ticks with persisted leftover-map
+singular values `σ_k` when leftoverMapAxisTickBadge returns a usable leftover-axis tick caption.
+Leftover-map comparison graphic leftover-map axis tick leftover-map axis share independently of leftover-map singular values
+(ADR 0331) captions leftover-map comparison graphic leftover-map axis ticks with persisted leftover-map
+axis share when leftoverMapComparePlotTickAxisBadge returns a usable leftover-map axis tick leftover-map
+axis share caption.
 Item complete-case coverage
 (ADR 0282) captions the leftover-map graphic with how many scored criteria
 entered the map. Item complete-case coverage on the pair list (ADR 0285)
diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index 2d798c8f2..dd2457d15 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -773,6 +773,9 @@ tick caption independently of leftover-map axis share.
 ADR 0330 captions leftover-axis ticks with persisted leftover-map
 singular values `σ_k` when leftoverMapAxisTickBadge returns a usable leftover-axis
 tick caption independently of leftover-map axis share.
+ADR 0331 captions leftover-map comparison graphic leftover-map axis ticks with persisted leftover-map
+axis share when leftoverMapComparePlotTickAxisBadge returns a usable leftover-map axis tick leftover-map
+axis share caption independently of leftover-map singular values.
 Click a post marker or a pair button
 opens that post. Those ADRs are the normative mathematical, storage, and
 display contracts. Leftover-map axis share
@@ -833,7 +836,8 @@ comparison graphic leftover-map axis leftover-map singular values as leftoverMap
 (ADR 0327), leftover-map comparison graphic leftover-map axis tick leftover-map singular values independently of leftover-map axis share
 (ADR 0328), leftover-map comparison leftover-axis tick leftover-map singular values independently of leftover-map axis share
 (ADR 0329), leftover-axis tick leftover-map singular values independently of leftover-map axis share
-(ADR 0330);
+(ADR 0330), leftover-map comparison graphic leftover-map axis tick leftover-map axis share independently of leftover-map singular values
+(ADR 0331);
 `POST .../rebuild` scores every grouping kind (post_admin). `make seed`
 folds A-100/B-200 Event Lineage fixtures (and the Riverbend calendar
 post) that already have constructed IRT cells into the same shared
diff --git a/CHANGELOG.d/2.88.0-leftover-map-compare-plot-tick-share-badge.md b/CHANGELOG.d/2.88.0-leftover-map-compare-plot-tick-share-badge.md
new file mode 100644
index 000000000..6a3e922d5
--- /dev/null
+++ b/CHANGELOG.d/2.88.0-leftover-map-compare-plot-tick-share-badge.md
@@ -0,0 +1,30 @@
+## 2.88.0 — Leftover-map axis share on leftover-map comparison graphic leftover-map axis ticks independently of leftover-map singular values
+
+- Caption leftover-map comparison graphic leftover-map axis ticks with persisted leftover-map
+  axis share through leftoverMapComparePlotTickAxisBadge independently of leftover-map
+  singular values (ADR 0331). After `make seed`, leftover-map comparison graphic leftover-map axis
+  ticks name persisted leftover-map axis share when leftoverMapComparePlotTickAxisBadge
+  returns a usable leftover-map axis tick leftover-map axis share caption even when leftover-map
+  singular values are omitted; click a leftover pair opens that post. A missing or
+  non-finite leftover-map axis share omits that leftover-map axis share tick caption and keeps
+  `leftover map comparison graphic leftover-map axis {k} tick {value}` or
+  `leftover map comparison graphic leftover-map axis {k} tick {value} σ {singular}`. Rank-0 unused
+  axes still name leftover-map axis share `0%`. Leftover-map comparison graphic leftover-map axis ticks stay
+  `leftover map comparison graphic leftover-map axis {k} tick {value} {share}%` when leftover-map
+  axis share is finite and `σ_k` omits, and
+  `leftover map comparison graphic leftover-map axis {k} tick {value} σ {singular} {share}%`
+  when both are finite so they stay distinct from leftover-map graphic leftover-map axis ticks
+  `leftover-map axis {k} tick {value} σ {singular}`, from leftover-map graphic leftover-map
+  axis `leftover-map axis {k} σ {value} ({share}%)`, from leftover-axis
+  `leftover axis {k} {share}%`, from comparison leftover-axis
+  `leftover map comparison leftover axis {k} {share}%`, from comparison graphic leftover-map
+  axis `leftover map comparison graphic leftover-map axis {k} σ {value} ({share}%)`, from comparison
+  leftover-axis ticks `leftover map comparison leftover axis {k} tick {value} σ {singular}`,
+  from leftover-axis ticks `leftover axis {k} tick {value} σ {singular}`, and from comparison
+  graphic leftover-map axis ticks
+  `leftover map comparison graphic leftover-map axis {k} tick {value} σ {singular}`. Do not invent
+  leftover-map axis share from `σ_k`. Do not invent `σ_k` from leftover-map axis
+  share. This increment does not change leftover-map graphic leftover-map axis ticks,
+  leftover-map comparison leftover-axis ticks, or leftover-axis ticks.
+  A finite negative leftover is shown, never clamped. Never invent a leftover score.
+  Never invent a theta. No new columns.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d9aa3a434..82bc23928 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,36 @@ All notable changes to this project are documented here. Format follows
 
 ### Added
 
+- Period leftover pairs now caption leftover-map comparison graphic leftover-map
+  axis ticks with persisted leftover-map axis share through leftoverMapComparePlotTickAxisBadge
+  independently of leftover-map singular values (ADR 0331 / v2.88.0). After `make seed`,
+  leftover-map comparison graphic leftover-map axis ticks name persisted leftover-map
+  axis share when leftoverMapComparePlotTickAxisBadge returns a usable leftover-map
+  axis tick leftover-map axis share caption even when leftover-map singular values are
+  omitted; click a leftover pair opens that post. A missing or non-finite leftover-map
+  axis share omits that leftover-map axis share tick caption and keeps
+  `leftover map comparison graphic leftover-map axis {k} tick {value}` or
+  `leftover map comparison graphic leftover-map axis {k} tick {value} σ {singular}`.
+  Rank-0 unused axes still name leftover-map axis share `0%`. Leftover-map comparison
+  graphic leftover-map axis ticks stay
+  `leftover map comparison graphic leftover-map axis {k} tick {value} {share}%` when leftover-map
+  axis share is finite and `σ_k` omits, and
+  `leftover map comparison graphic leftover-map axis {k} tick {value} σ {singular} {share}%`
+  when both are finite so they stay distinct from leftover-map graphic leftover-map axis ticks
+  `leftover-map axis {k} tick {value} σ {singular}`, from leftover-map graphic leftover-map
+  axis `leftover-map axis {k} σ {value} ({share}%)`, from leftover-axis
+  `leftover axis {k} {share}%`, from comparison leftover-axis
+  `leftover map comparison leftover axis {k} {share}%`, from comparison graphic leftover-map
+  axis `leftover map comparison graphic leftover-map axis {k} σ {value} ({share}%)`, from comparison
+  leftover-axis ticks `leftover map comparison leftover axis {k} tick {value} σ {singular}`,
+  from leftover-axis ticks `leftover axis {k} tick {value} σ {singular}`, and from comparison
+  graphic leftover-map axis ticks
+  `leftover map comparison graphic leftover-map axis {k} tick {value} σ {singular}`. Do not invent
+  leftover-map axis share from `σ_k`. Do not invent `σ_k` from leftover-map axis
+  share. This increment does not change leftover-map graphic leftover-map axis ticks,
+  leftover-map comparison leftover-axis ticks, or leftover-axis ticks. A finite negative leftover
+  is shown, never clamped. Never invent a leftover score or a theta. No new columns.
+
 - Period leftover pairs now caption leftover-axis ticks with persisted leftover-map
   singular values `σ_k` through leftoverMapAxisTickBadge independently of leftover-map
   axis share (ADR 0330 / v2.87.0). After `make seed`, leftover-axis ticks name
diff --git a/CLAUDE.md b/CLAUDE.md
index e9bf54c9b..8cef4b47f 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -49,7 +49,7 @@ cutoff. Global Ask optional `knowledge_cutoff` uses the same cover
 
 Create/start endpoint rules (ADR 0017 / 0021), tie-vs-miss similarity
 (ADR 0026), R&R catalog ids (ADR 0019 / 0027), leftover pairs
-(ADR 0048–0164 / 0182 / 0185 / 0201 / 0233 / 0266 / 0267 / 0268 / 0269 / 0270 / 0271 / 0272 / 0273 / 0274 / 0275 / 0276 / 0277 / 0278 / 0279 / 0280 / 0281 / 0282 / 0283 / 0284 / 0285 / 0286 / 0287 / 0288 / 0289 / 0290 / 0291 / 0292 / 0293 / 0294 / 0295 / 0296 / 0297 / 0298 / 0299 / 0300 / 0301 / 0302 / 0303 / 0304 / 0305 / 0306 / 0307 / 0308 / 0309 / 0310 / 0311 / 0312 / 0313 / 0314 / 0315 / 0316 / 0317 / 0318 / 0319 / 0320 / 0321 / 0322 / 0323 / 0324 / 0325 / 0326 / 0327 / 0328 / 0329 / 0330), occupational construct catalog search
+(ADR 0048–0164 / 0182 / 0185 / 0201 / 0233 / 0266 / 0267 / 0268 / 0269 / 0270 / 0271 / 0272 / 0273 / 0274 / 0275 / 0276 / 0277 / 0278 / 0279 / 0280 / 0281 / 0282 / 0283 / 0284 / 0285 / 0286 / 0287 / 0288 / 0289 / 0290 / 0291 / 0292 / 0293 / 0294 / 0295 / 0296 / 0297 / 0298 / 0299 / 0300 / 0301 / 0302 / 0303 / 0304 / 0305 / 0306 / 0307 / 0308 / 0309 / 0310 / 0311 / 0312 / 0313 / 0314 / 0315 / 0316 / 0317 / 0318 / 0319 / 0320 / 0321 / 0322 / 0323 / 0324 / 0325 / 0326 / 0327 / 0328 / 0329 / 0330 / 0331), occupational construct catalog search
 (ADR 0257), the text-channel embedding swap and cosine
 clamp (ADR 0190), per-edge channel-score persistence (ADR 0195),
 token-backed status notices (ADR 0220),
diff --git a/docs/adr/0148-leftover-map-axis-share.md b/docs/adr/0148-leftover-map-axis-share.md
index 0ee0869db..c1ecf1ff0 100644
--- a/docs/adr/0148-leftover-map-axis-share.md
+++ b/docs/adr/0148-leftover-map-axis-share.md
@@ -21,7 +21,9 @@
 [ADR 0329](0329-leftover-map-compare-axis-tick-badge.md)
 (leftover-map comparison leftover-axis tick leftover-map singular values independently of leftover-map axis share);
 [ADR 0330](0330-leftover-map-axis-tick-badge.md)
-(leftover-axis tick leftover-map singular values independently of leftover-map axis share)
+(leftover-axis tick leftover-map singular values independently of leftover-map axis share);
+[ADR 0331](0331-leftover-map-compare-plot-tick-share-badge.md)
+(leftover-map comparison graphic leftover-map axis tick leftover-map axis share independently of leftover-map singular values)
 
 ## Context
 
diff --git a/docs/adr/0320-leftover-map-compare-plot-ticks.md b/docs/adr/0320-leftover-map-compare-plot-ticks.md
index 4742ecf1c..2b89e4f6f 100644
--- a/docs/adr/0320-leftover-map-compare-plot-ticks.md
+++ b/docs/adr/0320-leftover-map-compare-plot-ticks.md
@@ -101,7 +101,9 @@ and distance are finite, `R̂ = ξ · ζ` and `d = ‖ξ − ζ‖`.
 Independent of leftover-map singular values on leftover-axis report badges.
 Independent of leftover-map comparison graphic leftover-map axis tick leftover-map
 singular values independently of leftover-map axis share
-([ADR 0328](0328-leftover-map-compare-plot-tick-axis-badge.md)).
+([ADR 0328](0328-leftover-map-compare-plot-tick-axis-badge.md)). Independent of leftover-map
+comparison graphic leftover-map axis tick leftover-map axis share independently of leftover-map
+singular values ([ADR 0331](0331-leftover-map-compare-plot-tick-share-badge.md)).
 
 ## References
 
diff --git a/docs/adr/0326-leftover-map-compare-plot-axis-badge.md b/docs/adr/0326-leftover-map-compare-plot-axis-badge.md
index d6f601a24..2ee4f8f48 100644
--- a/docs/adr/0326-leftover-map-compare-plot-axis-badge.md
+++ b/docs/adr/0326-leftover-map-compare-plot-axis-badge.md
@@ -121,7 +121,9 @@ Independent of leftover-map graphic leftover-map axis tick leftover-map singular
 values independently of leftover-map axis share
 ([ADR 0327](0327-leftover-map-plot-tick-axis-badge.md)). Independent of leftover-map
 comparison graphic leftover-map axis tick leftover-map singular values independently of leftover-map axis share
-([ADR 0328](0328-leftover-map-compare-plot-tick-axis-badge.md)).
+([ADR 0328](0328-leftover-map-compare-plot-tick-axis-badge.md)). Independent of leftover-map
+comparison graphic leftover-map axis tick leftover-map axis share independently of leftover-map
+singular values ([ADR 0331](0331-leftover-map-compare-plot-tick-share-badge.md)).
 
 ## References
 
diff --git a/docs/adr/0327-leftover-map-plot-tick-axis-badge.md b/docs/adr/0327-leftover-map-plot-tick-axis-badge.md
index f0bd6c0a5..8e8f279b2 100644
--- a/docs/adr/0327-leftover-map-plot-tick-axis-badge.md
+++ b/docs/adr/0327-leftover-map-plot-tick-axis-badge.md
@@ -110,7 +110,9 @@ share ([ADR 0325](0325-leftover-map-axis-singular-only.md)). Independent of left
 coordinate ticks on the grouping comparison leftover-map graphic
 ([ADR 0320](0320-leftover-map-compare-plot-ticks.md)). Independent of leftover-map
 comparison graphic leftover-map axis tick leftover-map singular values independently of leftover-map axis share
-([ADR 0328](0328-leftover-map-compare-plot-tick-axis-badge.md)).
+([ADR 0328](0328-leftover-map-compare-plot-tick-axis-badge.md)). Independent of leftover-map
+comparison graphic leftover-map axis tick leftover-map axis share independently of leftover-map
+singular values ([ADR 0331](0331-leftover-map-compare-plot-tick-share-badge.md)).
 
 ## References
 
diff --git a/docs/adr/0328-leftover-map-compare-plot-tick-axis-badge.md b/docs/adr/0328-leftover-map-compare-plot-tick-axis-badge.md
index f39915f14..ceba164af 100644
--- a/docs/adr/0328-leftover-map-compare-plot-tick-axis-badge.md
+++ b/docs/adr/0328-leftover-map-compare-plot-tick-axis-badge.md
@@ -112,7 +112,9 @@ share ([ADR 0325](0325-leftover-map-axis-singular-only.md)). Independent of left
 coordinate ticks on the grouping comparison leftover-map graphic
 ([ADR 0320](0320-leftover-map-compare-plot-ticks.md)). Independent of leftover-map
 comparison leftover-axis tick leftover-map singular values independently of leftover-map axis share
-([ADR 0329](0329-leftover-map-compare-axis-tick-badge.md)).
+([ADR 0329](0329-leftover-map-compare-axis-tick-badge.md)). Independent of leftover-map
+comparison graphic leftover-map axis tick leftover-map axis share independently of leftover-map
+singular values ([ADR 0331](0331-leftover-map-compare-plot-tick-share-badge.md)).
 
 ## References
 
diff --git a/docs/adr/0329-leftover-map-compare-axis-tick-badge.md b/docs/adr/0329-leftover-map-compare-axis-tick-badge.md
index bd849cf59..faea0787b 100644
--- a/docs/adr/0329-leftover-map-compare-axis-tick-badge.md
+++ b/docs/adr/0329-leftover-map-compare-axis-tick-badge.md
@@ -118,7 +118,9 @@ report badges on the grouping comparison strip
 comparison leftover-map graphic
 ([ADR 0320](0320-leftover-map-compare-plot-ticks.md)). Independent of leftover-axis
 tick leftover-map singular values independently of leftover-map axis share
-([ADR 0330](0330-leftover-map-axis-tick-badge.md)).
+([ADR 0330](0330-leftover-map-axis-tick-badge.md)). Independent of leftover-map
+comparison graphic leftover-map axis tick leftover-map axis share independently of leftover-map
+singular values ([ADR 0331](0331-leftover-map-compare-plot-tick-share-badge.md)).
 
 ## References
 
diff --git a/docs/adr/0330-leftover-map-axis-tick-badge.md b/docs/adr/0330-leftover-map-axis-tick-badge.md
index ee425ea24..a8189c827 100644
--- a/docs/adr/0330-leftover-map-axis-tick-badge.md
+++ b/docs/adr/0330-leftover-map-axis-tick-badge.md
@@ -98,7 +98,9 @@ axis tick leftover-map singular values independently of leftover-map axis share
 singular values independently of leftover-map axis share
 ([ADR 0327](0327-leftover-map-plot-tick-axis-badge.md)). Independent of leftover-map singular values on leftover-axis report badges
 independently of leftover-map axis share ([ADR 0325](0325-leftover-map-axis-singular-only.md)). Independent of leftover-map
-coordinate ticks on the leftover-map graphic ([ADR 0270](0270-leftover-map-coordinate-ticks.md)).
+coordinate ticks on the leftover-map graphic ([ADR 0270](0270-leftover-map-coordinate-ticks.md)). Independent of leftover-map
+comparison graphic leftover-map axis tick leftover-map axis share independently of leftover-map
+singular values ([ADR 0331](0331-leftover-map-compare-plot-tick-share-badge.md)).
 
 ## References
 
diff --git a/docs/adr/0331-leftover-map-compare-plot-tick-share-badge.md b/docs/adr/0331-leftover-map-compare-plot-tick-share-badge.md
new file mode 100644
index 000000000..1d014dbe0
--- /dev/null
+++ b/docs/adr/0331-leftover-map-compare-plot-tick-share-badge.md
@@ -0,0 +1,154 @@
+# ADR 0331 — Name leftover-map axis share on leftover-map comparison graphic leftover-map axis ticks independently of leftover-map singular values
+
+**Decision status:** Accepted
+**Date:** 2026-08-31
+
+Amends leftover-map comparison graphic leftover-map axis tick leftover-map singular
+values independently of leftover-map axis share
+([ADR 0328](0328-leftover-map-compare-plot-tick-axis-badge.md)), leftover-map
+coordinate ticks on the grouping comparison leftover-map graphic
+([ADR 0320](0320-leftover-map-compare-plot-ticks.md)), leftover-map comparison
+graphic leftover-map axis leftover-map singular values as leftoverMapComparePlotAxisBadge
+([ADR 0326](0326-leftover-map-compare-plot-axis-badge.md)), leftover-map axis share
+persistence ([ADR 0148](0148-leftover-map-axis-share.md)). Independent of leftover-map
+graphic leftover-map axis tick leftover-map singular values independently of leftover-map
+axis share ([ADR 0327](0327-leftover-map-plot-tick-axis-badge.md)). Independent of leftover-map
+comparison leftover-axis tick leftover-map singular values independently of leftover-map
+axis share ([ADR 0329](0329-leftover-map-compare-axis-tick-badge.md)). Independent of leftover-axis
+tick leftover-map singular values independently of leftover-map axis share
+([ADR 0330](0330-leftover-map-axis-tick-badge.md)).
+
+## Context
+
+ADR 0148 already persists leftover-map singular values `σ_k` and leftover-map
+axis share `σ_k² / Σ_j σ_j²`. ADR 0320 already ticks leftover-map comparison
+graphic leftover-map axes at persisted `ξ` / `ζ` projections as
+`leftover map comparison graphic leftover-map axis {k} tick {value}`. ADR 0326
+already captions leftover-map comparison graphic-display leftover-map axes with
+`σ_k` and leftover-map axis share through leftoverMapComparePlotAxisBadge, omitting
+each independently. ADR 0328 already captions leftover-map comparison graphic
+leftover-map axis ticks with `σ_k` through leftoverMapComparePlotTickAxisBadge
+independently of leftover-map axis share. Those leftover-map comparison graphic
+leftover-map axis ticks still omit leftover-map axis share, so a buyer who reads
+leftover-map comparison graphic leftover-map axis ticks can treat leftover-map
+coordinate ticks or leftover-map singular values as leftover-map structure without
+a next action. A missing or non-finite leftover-map axis share is not a leftover
+score and must omit independently of leftover-map singular values. Rank-0 unused
+axes still persist leftover-map axis share `0`. A finite negative leftover is
+shown, never clamped. Do not invent leftover-map axis share from `σ_k`. Do not
+invent `σ_k` from leftover-map axis share. Leftover-map graphic leftover-map axis
+ticks never name leftover-map axis share. Leftover-map comparison leftover-axis
+ticks (ADR 0329) and leftover-axis ticks (ADR 0330) never name leftover-map axis
+share this increment.
+
+This increment names leftover-map comparison graphic leftover-map axis ticks leftover-map
+axis share as leftoverMapComparePlotTickAxisBadge, matching leftoverMapComparePlotAxisBadge,
+leftoverMapCompareAxisBadge, leftoverMapPlotAxisBadge, leftoverMapAxisBadge, leftoverMapPlotTickAxisBadge,
+and leftoverMapComparePlotTickAxisBadge leftover-map singular values. Leftover-map
+comparison graphic leftover-map axis ticks stay
+`leftover map comparison graphic leftover-map axis {k} tick {value} {share}%` when leftover-map
+axis share is finite and `σ_k` omits, and
+`leftover map comparison graphic leftover-map axis {k} tick {value} σ {singular} {share}%`
+when both are finite, so they stay distinct from leftover-map graphic leftover-map axis ticks
+`leftover-map axis {k} tick {value} σ {singular}` (ADR 0327), from leftover-map graphic leftover-map axis
+`leftover-map axis {k} σ {value} ({share}%)` (ADR 0324), from leftover-axis
+`leftover axis {k} {share}%` (ADR 0325), from comparison leftover-axis
+`leftover map comparison leftover axis {k} {share}%` (ADR 0323), from comparison graphic leftover-map
+axis `leftover map comparison graphic leftover-map axis {k} σ {value} ({share}%)` (ADR 0326),
+from comparison leftover-axis ticks
+`leftover map comparison leftover axis {k} tick {value} σ {singular}` (ADR 0329),
+from leftover-axis ticks `leftover axis {k} tick {value} σ {singular}` (ADR 0330),
+and from comparison graphic leftover-map axis ticks
+`leftover map comparison graphic leftover-map axis {k} tick {value} σ {singular}` (ADR 0328).
+It does not add columns. Do not invent a leftover score. Do not invent a theta.
+
+This protected increment uses **0331** so it does not collide with leftover-axis
+tick leftover-map singular values independently of leftover-map axis share
+(0330), leftover-map comparison leftover-axis tick leftover-map singular values independently of leftover-map axis share
+(0329), leftover-map comparison graphic leftover-map axis tick leftover-map singular values independently of leftover-map axis share
+(0328), leftover-map graphic leftover-map axis tick leftover-map singular values independently of leftover-map axis share
+(0327), leftover-map comparison graphic leftover-map axis leftover-map singular values as leftoverMapComparePlotAxisBadge
+(0326), leftover-map coordinate ticks on the grouping comparison leftover-map graphic
+(0320), leftover-map axis share persistence (0148), or the dashboard stacks.
+
+## Decision
+
+On leftover-map comparison graphic leftover-map axis ticks, caption leftover-map axis `k`
+with persisted leftover-map axis share when leftoverMapComparePlotTickAxisBadge
+returns a usable leftover-map axis tick caption that includes that share.
+Share and singular value omit independently through that helper: no `σ_k` and no
+share keeps `leftover map comparison graphic leftover-map axis {k} tick {value}`;
+`σ_k` only is `leftover map comparison graphic leftover-map axis {k} tick {value} σ {singular}`;
+share only is `leftover map comparison graphic leftover-map axis {k} tick {value} {share}%`;
+both are `leftover map comparison graphic leftover-map axis {k} tick {value} σ {singular} {share}%`.
+A missing or non-finite leftover-map axis share omits that share tick caption and
+keeps a usable leftover-map comparison graphic leftover-map axis tick coordinate caption,
+including any leftover-map singular value. Rank-0 unused axes still name leftover-map
+axis share `0%`. Click a post marker to open that post. Criterion markers are not post
+buttons.
+
+Leftover-map comparison graphic leftover-map axis tick leftover-map axis share omits
+independently of leftover-map graphic leftover-map axis tick leftover-map singular values,
+leftover-map comparison leftover-axis tick leftover-map singular values, leftover-axis
+tick leftover-map singular values, leftover-map comparison graphic leftover-map axis leftover-map axis share, leftover-map graphic-display leftover-map axis
+leftover-map axis share, leftover-axis report badge leftover-map axis share, and leftover-map comparison leftover-axis
+leftover-map axis share. A missing leftover-map singular value omits leftover-map singular
+values and keeps a usable leftover-map comparison graphic leftover-map axis tick leftover-map
+axis share caption.
+
+This increment does not change leftover-map graphic leftover-map axis ticks. Those leftover-map
+graphic leftover-map axis ticks stay `leftover-map axis {axis} tick {value} σ {singular}`
+(ADR 0327) and never name leftover-map axis share. This increment does not change leftover-map
+comparison leftover-axis ticks or leftover-axis ticks. This increment does not persist leftover-map inner product, cosine, or length.
+
+Do not add SQL. Do not edit shipped migrations. Do not invent a leftover
+score. Do not invent a theta.
+
+## Consequences
+
+After `make seed`, leftover-map comparison graphic leftover-map axis ticks name persisted
+leftover-map axis share when leftoverMapComparePlotTickAxisBadge returns a usable
+leftover-map axis tick leftover-map axis share caption even when leftover-map singular
+values are omitted; click a leftover pair opens that post. Hidden posts stay hidden. Rank-0 unused
+axes still name leftover-map comparison graphic leftover-map axis tick leftover-map axis share `0%`. Leftover-map
+comparison graphic leftover-map axis tick leftover-map singular values independently of leftover-map axis share
+(ADR 0328), leftover-map graphic leftover-map axis tick leftover-map singular values independently of leftover-map axis share
+(ADR 0327), leftover-map comparison leftover-axis tick leftover-map singular values independently of leftover-map axis share
+(ADR 0329), leftover-axis tick leftover-map singular values independently of leftover-map axis share
+(ADR 0330), leftover-map comparison graphic leftover-map axis leftover-map singular values (ADR 0326), leftover-map
+graphic-display leftover-map singular values (ADR 0324), leftover-axis report badge
+leftover-map singular values independently of leftover-map axis share (ADR 0325),
+and grouping comparison leftover-map graphic leftover-map axis ticks (ADR 0320)
+remain.
+
+## Related
+
+Independent of leftover-map comparison graphic leftover-map axis tick leftover-map singular values
+independently of leftover-map axis share
+([ADR 0328](0328-leftover-map-compare-plot-tick-axis-badge.md)). Independent of leftover-map
+graphic leftover-map axis tick leftover-map singular values independently of leftover-map axis share
+([ADR 0327](0327-leftover-map-plot-tick-axis-badge.md)). Independent of leftover-map
+comparison leftover-axis tick leftover-map singular values independently of leftover-map axis share
+([ADR 0329](0329-leftover-map-compare-axis-tick-badge.md)). Independent of leftover-axis
+tick leftover-map singular values independently of leftover-map axis share
+([ADR 0330](0330-leftover-map-axis-tick-badge.md)). Independent of leftover-map
+comparison graphic leftover-map axis leftover-map singular values as leftoverMapComparePlotAxisBadge
+([ADR 0326](0326-leftover-map-compare-plot-axis-badge.md)). Independent of leftover-map
+singular values on leftover-map graphic-display axes
+([ADR 0324](0324-leftover-map-plot-axis-singular.md)). Independent of leftover-map
+coordinate ticks on the grouping comparison leftover-map graphic
+([ADR 0320](0320-leftover-map-compare-plot-ticks.md)). Independent of leftover-map
+axis share persistence ([ADR 0148](0148-leftover-map-axis-share.md)).
+
+## References
+
+Gabriel, K. R. (1971). The biplot graphic display of matrices with
+application to principal component analysis. *Biometrika, 58*(3),
+453–467. https://doi.org/10.1093/biomet/58.3.453
+
+Jeon, M., Jin, I. H., Schweinberger, M., & Baugh, S. (2021). Mapping
+unobserved item–respondent interactions: A latent space item response
+model with interaction map. *Psychometrika, 86*(2), 378–403.
+https://doi.org/10.1007/s11336-021-09762-5
+(LSIRM interaction `−γ‖ξ_j − ζ_i‖` after main effects
+`α_j − β_i`; typically `p = 2` for the interaction map.)
diff --git a/docs/product-technical-gap-baseline.md b/docs/product-technical-gap-baseline.md
index be94f06bf..737eac3c3 100644
--- a/docs/product-technical-gap-baseline.md
+++ b/docs/product-technical-gap-baseline.md
@@ -1,5 +1,27 @@
 # Product & Technical Gap Baseline
 
+> Exact-head loop overlay: 2026-08-31 13:56 KST. Protected `main` is
+> `cb187cadee5fb6c46d8a944815ccc154a1e028d1`. Writes work. Do not
+> self-approve. #871 leftover-map singular values on leftover-axis ticks
+> independently of leftover-map axis share (v2.87.0 / ADR 0330) is
+> `e9e4c2a`, stacked on #870 @ `b086d97`. Independent APPROVE is missing. Next
+> buyer increment on this cycle: leftover-map comparison graphic leftover-map axis
+> ticks naming persisted leftover-map axis share independently of leftover-map
+> singular values (ADR 0331 / v2.88.0) delivered locally on
+> `feat/leftover-map-compare-plot-tick-share-badge-v2880`. Caption persisted leftover-map
+> axis share on leftover-map comparison graphic leftover-map axis ticks when leftoverMapComparePlotTickAxisBadge
+> returns a usable leftover-map axis tick leftover-map axis share caption even when leftover-map
+> singular values omit. Distinct accessible names
+> `leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%` and
+> `leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%`.
+> Rank-0 unused axes still name leftover-map axis share `0%`. Share omits independently of
+> leftover-map singular values. Leftover-map graphic leftover-map axis ticks, leftover-map
+> comparison leftover-axis ticks, and leftover-axis ticks never name leftover-map axis share.
+> Do not invent leftover-map axis share from `σ_k`. Do not invent `σ_k` from leftover-map
+> axis share. Do not persist leftover-map inner product, cosine, or length. Stack onto #871.
+> Leave open for independent review. Do not squash-merge. Do not self-approve. Issues #79
+> and #87 stay open. Do not merge #808 without independent APPROVE. Never self-approve.
+
 > Exact-head loop overlay: 2026-08-31 13:28 KST. Protected `main` is
 > `cb187cadee5fb6c46d8a944815ccc154a1e028d1`. Writes work. Do not
 > self-approve. #870 leftover-map singular values on leftover-map comparison leftover-axis
diff --git a/frontend/package.json b/frontend/package.json
index 712ee4a66..92d3e5edf 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -1,7 +1,7 @@
 {
   "name": "frontend",
   "private": true,
-  "version": "2.87.0",
+  "version": "2.88.0",
   "type": "module",
   "scripts": {
     "dev": "vite",
diff --git a/frontend/src/App.test.tsx b/frontend/src/App.test.tsx
index 25999ef95..61eeed3c9 100644
--- a/frontend/src/App.test.tsx
+++ b/frontend/src/App.test.tsx
@@ -4738,7 +4738,7 @@ describe("App, authenticated", () => {
     ).not.toBeInTheDocument();
     expect(
       within(screen.getByLabelText("Grouping comparison")).getByLabelText(
-        "leftover map comparison graphic leftover-map axis 1 tick +0.50 σ 1.84",
+        "leftover map comparison graphic leftover-map axis 1 tick +0.50 σ 1.84 82%",
       ),
     ).toBeInTheDocument();
     expect(
diff --git a/frontend/src/components/LeftoverMapPlot.test.tsx b/frontend/src/components/LeftoverMapPlot.test.tsx
index 65d3a5e5e..be6c6f7e4 100644
--- a/frontend/src/components/LeftoverMapPlot.test.tsx
+++ b/frontend/src/components/LeftoverMapPlot.test.tsx
@@ -2695,17 +2695,20 @@ describe("LeftoverMapPlot", () => {
       />,
     );
     expect(
-      screen.getByLabelText("leftover map comparison graphic leftover-map axis 1 tick +0.50 σ 1.84"),
+      screen.getByLabelText("leftover map comparison graphic leftover-map axis 1 tick +0.50 σ 1.84 82%"),
     ).toBeInTheDocument();
     expect(
-      screen.getByLabelText("leftover map comparison graphic leftover-map axis 2 tick −0.02 σ 0.86"),
+      screen.getByLabelText("leftover map comparison graphic leftover-map axis 2 tick −0.02 σ 0.86 18%"),
     ).toBeInTheDocument();
     expect(
-      screen.getByLabelText("leftover map comparison graphic leftover-map axis 1 tick 0.00 σ 1.84"),
+      screen.getByLabelText("leftover map comparison graphic leftover-map axis 1 tick 0.00 σ 1.84 82%"),
     ).toBeInTheDocument();
     expect(
       screen.queryByLabelText("leftover map comparison graphic leftover-map axis 1 tick +0.50"),
     ).not.toBeInTheDocument();
+    expect(
+      screen.queryByLabelText("leftover map comparison graphic leftover-map axis 1 tick +0.50 σ 1.84"),
+    ).not.toBeInTheDocument();
     expect(screen.queryByLabelText("leftover-map axis 1 tick +0.50")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("leftover-map axis 1 tick +0.50 σ 1.84")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("leftover-map axis 2 tick −0.02")).not.toBeInTheDocument();
@@ -2766,7 +2769,7 @@ describe("LeftoverMapPlot", () => {
       />,
     );
     expect(
-      screen.getAllByLabelText("leftover map comparison graphic leftover-map axis 1 tick 0.00 σ 0.00").length,
+      screen.getAllByLabelText("leftover map comparison graphic leftover-map axis 1 tick 0.00 σ 0.00 0%").length,
     ).toBeGreaterThan(0);
     expect(
       screen.queryByLabelText("leftover map comparison graphic leftover-map axis 1 tick +1.00"),
@@ -2822,10 +2825,10 @@ describe("LeftoverMapPlot", () => {
       />,
     );
     expect(
-      screen.getByLabelText("leftover map comparison graphic leftover-map axis 1 tick 0.00 σ 0.00"),
+      screen.getByLabelText("leftover map comparison graphic leftover-map axis 1 tick 0.00 σ 0.00 0%"),
     ).toBeInTheDocument();
     expect(
-      screen.getByLabelText("leftover map comparison graphic leftover-map axis 2 tick 0.00 σ 0.00"),
+      screen.getByLabelText("leftover map comparison graphic leftover-map axis 2 tick 0.00 σ 0.00 0%"),
     ).toBeInTheDocument();
     expect(screen.queryByLabelText("leftover-map axis 1 tick 0.00")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("leftover-map axis 2 tick 0.00")).not.toBeInTheDocument();
@@ -2884,10 +2887,10 @@ describe("LeftoverMapPlot", () => {
       />,
     );
     expect(
-      screen.getByLabelText("leftover map comparison graphic leftover-map axis 1 tick +0.50"),
+      screen.getByLabelText("leftover map comparison graphic leftover-map axis 1 tick +0.50 82%"),
     ).toBeInTheDocument();
     expect(
-      screen.getByLabelText("leftover map comparison graphic leftover-map axis 2 tick −0.02"),
+      screen.getByLabelText("leftover map comparison graphic leftover-map axis 2 tick −0.02 18%"),
     ).toBeInTheDocument();
     expect(
       screen.queryByLabelText("leftover map comparison graphic leftover-map axis 1 tick +0.50 σ 1.84"),
@@ -2895,4 +2898,33 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
     expect(screen.getByText("leftover map comparison axis 2 (18%)")).toBeInTheDocument();
   });
+
+  it("captions leftover-map comparison graphic leftover-map axis ticks with leftover-map axis share independently of leftover-map singular values", () => {
+    render(
+      <LeftoverMapPlot
+        pairs={PAIRS}
+        leftoverMapAxes={[
+          { axis_index: 1, leftover_singular_value: 1.84, leftover_share: 0.82 },
+          { axis_index: 2, leftover_singular_value: Number.NaN, leftover_share: 0.18 },
+        ]}
+        criterionLabel={criterionLabel}
+        onSelectPost={vi.fn()}
+        variant="comparison"
+      />,
+    );
+    expect(
+      screen.getByLabelText("leftover map comparison graphic leftover-map axis 1 tick +0.50 σ 1.84 82%"),
+    ).toBeInTheDocument();
+    expect(
+      screen.getByLabelText("leftover map comparison graphic leftover-map axis 2 tick −0.02 18%"),
+    ).toBeInTheDocument();
+    expect(
+      screen.queryByLabelText("leftover map comparison graphic leftover-map axis 1 tick +0.50 σ 1.84"),
+    ).not.toBeInTheDocument();
+    expect(
+      screen.queryByLabelText("leftover map comparison graphic leftover-map axis 2 tick −0.02 σ 0.86"),
+    ).not.toBeInTheDocument();
+    expect(screen.queryByLabelText("leftover-map axis 1 tick +0.50 σ 1.84")).not.toBeInTheDocument();
+    expect(screen.queryByText("leftover axis 1 tick +0.50 82%")).not.toBeInTheDocument();
+  });
 });
diff --git a/frontend/src/components/LeftoverMapPlot.tsx b/frontend/src/components/LeftoverMapPlot.tsx
index 9e862e0cc..b592416b6 100644
--- a/frontend/src/components/LeftoverMapPlot.tsx
+++ b/frontend/src/components/LeftoverMapPlot.tsx
@@ -106,7 +106,13 @@ function leftoverMapPlotTickText(
 ): string {
   const leftoverSingular = leftoverSingularForAxis(leftoverMapAxes, axisIndex);
   if (variant === "comparison") {
-    const badge = leftoverMapComparePlotTickAxisBadge(axisIndex, tickLabel, leftoverSingular);
+    const leftoverShare = leftoverShareForAxis(leftoverMapAxes, axisIndex);
+    const badge = leftoverMapComparePlotTickAxisBadge(
+      axisIndex,
+      tickLabel,
+      leftoverSingular,
+      leftoverShare,
+    );
     return tf(badge.key, badge.values);
   }
   const badge = leftoverMapPlotTickAxisBadge(axisIndex, tickLabel, leftoverSingular);
@@ -218,6 +224,9 @@ function leftoverMapPlotTickText(
  * ADR 0328 fail-closes leftover-map comparison graphic leftover-map axis ticks leftover-map
  * singular values through leftoverMapComparePlotTickAxisBadge independently of leftover-map
  * axis share.
+ * ADR 0331 fail-closes leftover-map comparison graphic leftover-map axis ticks leftover-map
+ * axis share through leftoverMapComparePlotTickAxisBadge independently of leftover-map
+ * singular values.
  * Never invent a leftover score.
  */
 export function LeftoverMapPlot({
diff --git a/frontend/src/i18n.test.ts b/frontend/src/i18n.test.ts
index 00f665876..324616623 100644
--- a/frontend/src/i18n.test.ts
+++ b/frontend/src/i18n.test.ts
@@ -113,6 +113,8 @@ describe("i18n", () => {
     "leftover map comparison graphic leftover-map distance {label}",
     "leftover map comparison graphic leftover-map axis {axis} tick {value}",
     "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular}",
+    "leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%",
+    "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%",
     "leftover map comparison graphic leftover-map axis {axis} σ {value}",
     "leftover map comparison graphic leftover-map axis {axis} σ {value} ({share}%)",
     "leftover map comparison leftover axis {axis} σ {value}",
@@ -724,6 +726,48 @@ describe("i18n", () => {
     },
   );
 
+  it.each([
+    ["ko", "잔여 지도 비교 그림 축 1 눈금 +0.50 82%"],
+    ["zh", "残差地图比较图形轴 1 刻度 +0.50 82%"],
+    ["ja", "残差マップの比較図軸 1 目盛 +0.50 82%"],
+    ["vi", "vạch trục đồ họa so sánh bản đồ phần dư 1 +0.50 82%"],
+  ] as const)(
+    "formats leftover map comparison graphic leftover-map axis tick leftover-map axis share in %s",
+    (locale, expected) => {
+      setLocale(locale);
+      expect(
+        tf("leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%", {
+          axis: 1,
+          value: "+0.50",
+          share: "82",
+        }),
+      ).toBe(expected);
+    },
+  );
+
+  it.each([
+    ["ko", "잔여 지도 비교 그림 축 1 눈금 +0.50 σ 1.84 82%"],
+    ["zh", "残差地图比较图形轴 1 刻度 +0.50 σ 1.84 82%"],
+    ["ja", "残差マップの比較図軸 1 目盛 +0.50 σ 1.84 82%"],
+    ["vi", "vạch trục đồ họa so sánh bản đồ phần dư 1 +0.50 σ 1.84 82%"],
+  ] as const)(
+    "formats leftover map comparison graphic leftover-map axis tick leftover-map singular values and leftover-map axis share in %s",
+    (locale, expected) => {
+      setLocale(locale);
+      expect(
+        tf(
+          "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%",
+          {
+            axis: 1,
+            value: "+0.50",
+            singular: "1.84",
+            share: "82",
+          },
+        ),
+      ).toBe(expected);
+    },
+  );
+
   it.each([
     ["ko", "잔여 지도 비교 그림 축 1 σ 1.84"],
     ["zh", "残差地图比较图形轴 1 σ 1.84"],
diff --git a/frontend/src/i18n.ts b/frontend/src/i18n.ts
index 745722b7f..ff8b1abbb 100644
--- a/frontend/src/i18n.ts
+++ b/frontend/src/i18n.ts
@@ -299,6 +299,10 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "leftover map comparison graphic leftover-map axis {axis} tick {value}": "잔여 지도 비교 그림 축 {axis} 눈금 {value}",
     "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular}":
       "잔여 지도 비교 그림 축 {axis} 눈금 {value} σ {singular}",
+    "leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%":
+      "잔여 지도 비교 그림 축 {axis} 눈금 {value} {share}%",
+    "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%":
+      "잔여 지도 비교 그림 축 {axis} 눈금 {value} σ {singular} {share}%",
     "leftover map comparison graphic leftover-map axis {axis} σ {value}": "잔여 지도 비교 그림 축 {axis} σ {value}",
     "leftover map comparison graphic leftover-map axis {axis} σ {value} ({share}%)":
       "잔여 지도 비교 그림 축 {axis} σ {value} ({share}%)",
@@ -964,6 +968,10 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "leftover map comparison graphic leftover-map axis {axis} tick {value}": "残差地图比较图形轴 {axis} 刻度 {value}",
     "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular}":
       "残差地图比较图形轴 {axis} 刻度 {value} σ {singular}",
+    "leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%":
+      "残差地图比较图形轴 {axis} 刻度 {value} {share}%",
+    "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%":
+      "残差地图比较图形轴 {axis} 刻度 {value} σ {singular} {share}%",
     "leftover map comparison graphic leftover-map axis {axis} σ {value}": "残差地图比较图形轴 {axis} σ {value}",
     "leftover map comparison graphic leftover-map axis {axis} σ {value} ({share}%)":
       "残差地图比较图形轴 {axis} σ {value} ({share}%)",
@@ -1650,6 +1658,10 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "leftover map comparison graphic leftover-map axis {axis} tick {value}": "残差マップの比較図軸 {axis} 目盛 {value}",
     "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular}":
       "残差マップの比較図軸 {axis} 目盛 {value} σ {singular}",
+    "leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%":
+      "残差マップの比較図軸 {axis} 目盛 {value} {share}%",
+    "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%":
+      "残差マップの比較図軸 {axis} 目盛 {value} σ {singular} {share}%",
     "leftover map comparison graphic leftover-map axis {axis} σ {value}": "残差マップの比較図軸 {axis} σ {value}",
     "leftover map comparison graphic leftover-map axis {axis} σ {value} ({share}%)":
       "残差マップの比較図軸 {axis} σ {value} ({share}%)",
@@ -2315,6 +2327,10 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "leftover map comparison graphic leftover-map axis {axis} tick {value}": "vạch trục đồ họa so sánh bản đồ phần dư {axis} {value}",
     "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular}":
       "vạch trục đồ họa so sánh bản đồ phần dư {axis} {value} σ {singular}",
+    "leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%":
+      "vạch trục đồ họa so sánh bản đồ phần dư {axis} {value} {share}%",
+    "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%":
+      "vạch trục đồ họa so sánh bản đồ phần dư {axis} {value} σ {singular} {share}%",
     "leftover map comparison graphic leftover-map axis {axis} σ {value}":
       "trục đồ họa so sánh bản đồ phần dư {axis} σ {value}",
     "leftover map comparison graphic leftover-map axis {axis} σ {value} ({share}%)":
diff --git a/frontend/src/leftoverMapAxisBadge.test.ts b/frontend/src/leftoverMapAxisBadge.test.ts
index 5f3469b10..3d4bf13f5 100644
--- a/frontend/src/leftoverMapAxisBadge.test.ts
+++ b/frontend/src/leftoverMapAxisBadge.test.ts
@@ -201,6 +201,9 @@ describe("leftover-axis leftover-axis tick leftover-map singular values", () =>
     expect(leftoverMapAxisTickBadge(1, "+0.50", 1.84).key).not.toBe(
       leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84).key,
     );
+    expect(leftoverMapAxisTickBadge(1, "+0.50", 1.84).key).not.toBe(
+      leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84, 0.82).key,
+    );
     expect(leftoverMapAxisTickBadge(1, "+0.50", 1.84).key).not.toBe(
       leftoverMapAxisBadge(1, 1.84, null)?.key,
     );
diff --git a/frontend/src/leftoverMapAxisBadge.ts b/frontend/src/leftoverMapAxisBadge.ts
index 498f68d9d..9aefed2dd 100644
--- a/frontend/src/leftoverMapAxisBadge.ts
+++ b/frontend/src/leftoverMapAxisBadge.ts
@@ -14,6 +14,8 @@
  *  leftoverMapCompareAxisTickBadge, not this helper.
  *  ADR 0330 names leftover-map leftover-axis ticks leftover-map singular
  *  values as leftoverMapAxisTickBadge independently of leftover-map axis share.
+ *  ADR 0331 captions leftover-map comparison graphic leftover-map axis ticks leftover-map
+ *  axis share as leftoverMapComparePlotTickAxisBadge, not this helper.
  */
 
 import type { LeftoverMapAxis } from "./api";
diff --git a/frontend/src/leftoverMapPlotAxisSingular.test.ts b/frontend/src/leftoverMapPlotAxisSingular.test.ts
index 520fb2677..5b22701b1 100644
--- a/frontend/src/leftoverMapPlotAxisSingular.test.ts
+++ b/frontend/src/leftoverMapPlotAxisSingular.test.ts
@@ -17,7 +17,9 @@ import {
   LEFTOVER_MAP_COMPARE_AXIS_TICK_SINGULAR,
   LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR,
   LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR_SHARE,
+  LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE,
   LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR,
+  LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE,
   LEFTOVER_MAP_PLOT_AXIS_SINGULAR,
   LEFTOVER_MAP_PLOT_AXIS_SINGULAR_SHARE,
   LEFTOVER_MAP_PLOT_TICK_SINGULAR,
@@ -540,3 +542,113 @@ describe("leftover-map comparison leftover-axis tick leftover-map singular value
     );
   });
 });
+
+describe("leftover-map comparison graphic leftover-map axis tick leftover-map axis share", () => {
+  it("names persisted leftover-map axis share on leftover-map comparison graphic leftover-map axis ticks independently of leftover-map singular values", () => {
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84, 0.82)).toEqual({
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE,
+      values: { axis: 1, value: "+0.50", singular: "1.84", share: "82" },
+    });
+    expect(leftoverMapComparePlotTickAxisBadge(2, "−0.02", 0.86, 0.18)).toEqual({
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE,
+      values: { axis: 2, value: "−0.02", singular: "0.86", share: "18" },
+    });
+  });
+
+  it("names leftover-map axis share on leftover-map comparison graphic leftover-map axis ticks when leftover-map singular values omit", () => {
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", Number.NaN, 0.82)).toEqual({
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE,
+      values: { axis: 1, value: "+0.50", share: "82" },
+    });
+    expect(leftoverMapComparePlotTickAxisBadge(2, "−0.02", -0.01, 0.18)).toEqual({
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE,
+      values: { axis: 2, value: "−0.02", share: "18" },
+    });
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", null, 0.82).values.singular).toBeUndefined();
+  });
+
+  it("names rank-0 zero leftover-map axis share on leftover-map comparison graphic leftover-map axis ticks", () => {
+    expect(leftoverMapComparePlotTickAxisBadge(1, "0.00", 0, 0)).toEqual({
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE,
+      values: { axis: 1, value: "0.00", singular: "0.00", share: "0" },
+    });
+    expect(leftoverMapComparePlotTickAxisBadge(1, "0.00", null, 0)).toEqual({
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE,
+      values: { axis: 1, value: "0.00", share: "0" },
+    });
+  });
+
+  it("omits leftover-map axis share independently of leftover-map singular values", () => {
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84, Number.NaN)).toEqual({
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR,
+      values: { axis: 1, value: "+0.50", singular: "1.84" },
+    });
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84, null)).toEqual({
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR,
+      values: { axis: 1, value: "+0.50", singular: "1.84" },
+    });
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", Number.NaN, Number.NaN)).toEqual({
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK,
+      values: { axis: 1, value: "+0.50" },
+    });
+  });
+
+  it("does not invent leftover-map axis share from leftover-map singular values", () => {
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84, undefined).key).toBe(
+      LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR,
+    );
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84, undefined).values.share).toBeUndefined();
+  });
+
+  it("does not invent leftover-map singular values from leftover-map axis share", () => {
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", undefined, 0.82).key).toBe(
+      LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE,
+    );
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", undefined, 0.82).values.singular).toBeUndefined();
+  });
+
+  it("does not name leftover-map axis share on leftover-map graphic leftover-map axis ticks", () => {
+    expect(leftoverMapPlotTickAxisBadge(1, "+0.50", 1.84).values.share).toBeUndefined();
+    expect(leftoverMapPlotTickAxisBadge(1, "+0.50", 1.84).key).toBe(LEFTOVER_MAP_PLOT_TICK_SINGULAR);
+    expect(leftoverMapPlotTickAxisBadge(1, "+0.50", 1.84).key).not.toBe(
+      leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84, 0.82).key,
+    );
+  });
+
+  it("stays distinct from leftover-axis, leftover-map graphic axis, leftover-map graphic tick, comparison leftover-axis, and comparison graphic copy", () => {
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE).toBe(
+      "leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%",
+    );
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE).toBe(
+      "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%",
+    );
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE).not.toBe(LEFTOVER_MAP_COMPARE_PLOT_TICK);
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE).not.toBe(LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR);
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE).not.toBe(LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE);
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE).not.toBe(LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR);
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE).not.toBe(LEFTOVER_MAP_PLOT_TICK_SINGULAR);
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE).not.toBe(LEFTOVER_MAP_COMPARE_PLOT_AXIS_SHARE);
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE).not.toBe(
+      LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR_SHARE,
+    );
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE).not.toBe(
+      LEFTOVER_MAP_COMPARE_AXIS_SINGULAR_SHARE,
+    );
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE).not.toBe(LEFTOVER_MAP_COMPARE_AXIS_TICK);
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE).not.toBe(
+      LEFTOVER_MAP_COMPARE_AXIS_TICK_SINGULAR,
+    );
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84, 0.82).key).not.toBe(
+      leftoverMapComparePlotAxisBadge(1, 1.84, 0.82)?.key,
+    );
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", null, 0.82).key).not.toBe(
+      leftoverMapComparePlotAxisBadge(1, null, 0.82)?.key,
+    );
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84, 0.82).key).not.toBe(
+      leftoverMapPlotTickAxisBadge(1, "+0.50", 1.84).key,
+    );
+    expect(leftoverMapComparePlotTickAxisBadge(1, "+0.50", 1.84, 0.82).key).not.toBe(
+      leftoverMapCompareAxisTickBadge(1, "+0.50", 1.84).key,
+    );
+  });
+});
diff --git a/frontend/src/leftoverMapPlotAxisSingular.ts b/frontend/src/leftoverMapPlotAxisSingular.ts
index ab64a2f55..380ecf2a5 100644
--- a/frontend/src/leftoverMapPlotAxisSingular.ts
+++ b/frontend/src/leftoverMapPlotAxisSingular.ts
@@ -17,6 +17,9 @@
  *  ADR 0330 names leftover-map leftover-axis ticks leftover-map singular
  *  values as leftoverMapAxisTickBadge independently of leftover-map axis share,
  *  not leftoverMapCompareAxisTickBadge.
+ *  ADR 0331 names leftover-map comparison graphic leftover-map axis ticks leftover-map
+ *  axis share as leftoverMapComparePlotTickAxisBadge independently of leftover-map
+ *  singular values.
  */
 
 import type { LeftoverMapAxis } from "./api";
@@ -47,6 +50,12 @@ export const LEFTOVER_MAP_PLOT_TICK_SINGULAR =
 export const LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR =
   "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular}";
 
+export const LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE =
+  "leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%";
+
+export const LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE =
+  "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%";
+
 export const LEFTOVER_MAP_COMPARE_AXIS_SINGULAR =
   "leftover map comparison leftover axis {axis} σ {value}";
 
@@ -190,14 +199,28 @@ export function leftoverMapComparePlotTickAxisBadge(
   axisIndex: number,
   tickLabel: string,
   leftoverSingular: number | null | undefined,
+  leftoverShare?: number | null,
 ): LeftoverMapCompareAxisBadge {
   const singular = formatLeftoverMapPlotAxisSingular(leftoverSingular);
-  if (singular === null) {
+  const percent = formatLeftoverMapPlotAxisShare(leftoverShare);
+  if (singular === null && percent === null) {
     return { key: LEFTOVER_MAP_COMPARE_PLOT_TICK, values: { axis: axisIndex, value: tickLabel } };
   }
+  if (singular === null && percent !== null) {
+    return {
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SHARE,
+      values: { axis: axisIndex, value: tickLabel, share: percent },
+    };
+  }
+  if (singular !== null && percent === null) {
+    return {
+      key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR,
+      values: { axis: axisIndex, value: tickLabel, singular },
+    };
+  }
   return {
-    key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR,
-    values: { axis: axisIndex, value: tickLabel, singular },
+    key: LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE,
+    values: { axis: axisIndex, value: tickLabel, singular: singular as string, share: percent as string },
   };
 }
 
diff --git a/frontend/src/leftoverMapPlotLayout.test.ts b/frontend/src/leftoverMapPlotLayout.test.ts
index c1b68cffd..8d0be0d3a 100644
--- a/frontend/src/leftoverMapPlotLayout.test.ts
+++ b/frontend/src/leftoverMapPlotLayout.test.ts
@@ -1375,6 +1375,12 @@ describe("leftover map comparison graphic labels", () => {
     expect(LEFTOVER_MAP_COMPARE_PLOT_TICK).not.toBe(
       "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular}",
     );
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK).not.toBe(
+      "leftover map comparison graphic leftover-map axis {axis} tick {value} {share}%",
+    );
+    expect(LEFTOVER_MAP_COMPARE_PLOT_TICK).not.toBe(
+      "leftover map comparison graphic leftover-map axis {axis} tick {value} σ {singular} {share}%",
+    );
     expect(LEFTOVER_MAP_COMPARE_PLOT_TICK).not.toBe(
       "leftover map comparison leftover axis {axis} σ {value}",
     );
diff --git a/frontend/src/leftoverMapPlotLayout.ts b/frontend/src/leftoverMapPlotLayout.ts
index 9d460a322..09eff6059 100644
--- a/frontend/src/leftoverMapPlotLayout.ts
+++ b/frontend/src/leftoverMapPlotLayout.ts
@@ -103,6 +103,9 @@
  *  ADR 0330 fail-closes leftover-map leftover-axis ticks leftover-map
  *  singular values through leftoverMapAxisTickBadge independently of leftover-map
  *  axis share, not this graphic.
+ *  ADR 0331 fail-closes leftover-map comparison graphic leftover-map axis ticks leftover-map
+ *  axis share through leftoverMapComparePlotTickAxisBadge independently of leftover-map
+ *  singular values.
  */
 
 import { formatLeftoverMapCoordinatePair } from "./leftoverMapCoordinates";
diff --git a/pyproject.toml b/pyproject.toml
index 4cbf8bd6e..db01d587c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "lineageweave"
-version = "2.87.0"
+version = "2.88.0"
 description = "Reconstructs git-branch-style lineage DAGs from scattered short records using multi-channel score fusion and LLM adjudication."
 readme = "README.md"
 license = { text = "MIT" }