diff --git a/docs/superpowers/plans/2026-06-08-form-field-grouping.md b/docs/superpowers/plans/2026-06-08-form-field-grouping.md
new file mode 100644
index 0000000..4178865
--- /dev/null
+++ b/docs/superpowers/plans/2026-06-08-form-field-grouping.md
@@ -0,0 +1,191 @@
+# Object-Form Flexible-Field Grouping — Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Group the object form's flexible-field inputs by `def.group` (definition order, "Other" last) with subheadings, reusing one shared helper so the form and the detail view group identically.
+
+**Architecture:** Extract the detail view's defs-grouping into `lib/group-fields.ts` (`groupDefinitions`), unit-test it, refactor `object-detail.tsx` to use it (output-preserving), then render the form's flexible block grouped via the same helper.
+
+**Tech Stack:** React 19 + TS + pnpm, react-hook-form, react-i18next, Vitest + RTL. Test runner: `pnpm test` (single pass).
+
+**Conventions:** pnpm; **no `any`/`eslint-disable`/`@ts-ignore`**; no codename; en/sv parity (no new keys); app source double-quote+semicolon; token classes only; no behavior change to the form (inputs/validation/submission).
+
+**Spec:** `docs/superpowers/specs/2026-06-08-form-field-grouping-design.md`
+
+**Key facts:**
+- `object-detail.tsx` builds groups inline (`const other = t("fields.other"); const present = (definitions ?? []).filter(d => object.fields[d.key] != null); const groups: { group, defs }[] = []; for (const def of present) { … } ` + orphan push + `groups.sort((a,b) => Number(a.group===other) - Number(b.group===other));`). Type alias `FieldDefinitionView = components["schemas"]["FieldDefinitionView"]` already imported.
+- `object-form.tsx` flexible block: `<fieldset className="space-y-3 border-t pt-3"><legend className="label-caption">{t("form.flexibleHeading")}</legend>{definitions.map((def) => <div key={def.key}><FieldInput definition={def} form={form} />{errors.fields?.[def.key] && <p role="alert" className="text-xs text-destructive">{errors.fields[def.key]?.message ?? t("form.required")}</p>}</div>)}</fieldset>`.
+- Field-def fixtures have `group: "Description"` (inscription) and `group: null` (the rest).
+- `sr-only` is a valid utility (used in the #52 skip link). `fields.other` + `form.flexibleHeading` are existing i18n keys.
+
+---
+
+# Task 1: Shared `groupDefinitions` helper + unit test + detail refactor
+
+**Files:** `web/src/lib/group-fields.ts` (new), `web/src/lib/group-fields.test.ts` (new), `web/src/objects/object-detail.tsx`.
+
+- [ ] **Step 1: `web/src/lib/group-fields.ts`:**
+```ts
+import type { components } from "../api/schema";
+
+type FieldDefinitionView = components["schemas"]["FieldDefinitionView"];
+
+export type FieldGroup = { group: string; defs: FieldDefinitionView[] };
+
+/** Group field definitions by `def.group` (trimmed), preserving definition order
+ *  within and across groups; ungrouped defs fall into a trailing `otherLabel` bucket. */
+export function groupDefinitions(
+  definitions: FieldDefinitionView[],
+  otherLabel: string,
+): FieldGroup[] {
+  const groups: FieldGroup[] = [];
+  for (const def of definitions) {
+    const group = def.group?.trim() ? def.group : otherLabel;
+    let bucket = groups.find((g) => g.group === group);
+    if (!bucket) {
+      bucket = { group, defs: [] };
+      groups.push(bucket);
+    }
+    bucket.defs.push(def);
+  }
+  groups.sort((a, b) => Number(a.group === otherLabel) - Number(b.group === otherLabel));
+  return groups;
+}
+```
+
+- [ ] **Step 2: `web/src/lib/group-fields.test.ts`** (write + run, must pass):
+```ts
+import { expect, test } from "vitest";
+import { groupDefinitions } from "./group-fields";
+
+type Def = { key: string; group?: string | null };
+const def = (key: string, group: string | null): Def => ({ key, group });
+
+function keysByGroup(defs: Def[]) {
+  // cast through unknown — the helper only reads key/group
+  return groupDefinitions(defs as never, "Other").map((g) => ({
+    group: g.group,
+    keys: g.defs.map((d) => (d as unknown as Def).key),
+  }));
+}
+
+test("preserves definition order within and across groups; Other is last", () => {
+  const result = keysByGroup([
+    def("a", "Description"),
+    def("b", null),
+    def("c", "Description"),
+    def("d", "Provenance"),
+    def("e", "  "),
+  ]);
+  expect(result).toEqual([
+    { group: "Description", keys: ["a", "c"] },
+    { group: "Provenance", keys: ["d"] },
+    { group: "Other", keys: ["b", "e"] },
+  ]);
+});
+
+test("all-ungrouped → a single trailing Other group", () => {
+  expect(keysByGroup([def("x", null), def("y", null)])).toEqual([
+    { group: "Other", keys: ["x", "y"] },
+  ]);
+});
+```
+Run: `cd web && pnpm vitest run src/lib/group-fields.test.ts` → PASS (2 tests). (If the `as never`/`as unknown` casts trip lint, type the test `def` as the real `FieldDefinitionView` partial via `Partial<…> as …` — keep it lint-clean and `any`-free; the helper only reads `key`/`group`.)
+
+- [ ] **Step 3: Refactor `object-detail.tsx`** to use the helper. Add `import { groupDefinitions } from "../lib/group-fields";`. Replace the inline group-building loop + the final `groups.sort(...)` with:
+```tsx
+const other = t("fields.other");
+const present = (definitions ?? []).filter((d) => object.fields[d.key] != null);
+const groups = groupDefinitions(present, other);
+```
+Keep the orphan handling exactly as-is AFTER this (`const definedKeys = …; const orphans = …; if (orphans.length > 0 && !groups.some((g) => g.group === other)) groups.push({ group: other, defs: [] });`). The appended Other bucket remains last (the helper already put any Other last, and appending when absent adds it at the end). Do NOT re-add a `groups.sort(...)` — appending keeps Other last. The render (`groups.map(...)`) is unchanged.
+
+- [ ] **Step 4: Verify (vitest ONCE):** `cd web && pnpm vitest run src/lib/group-fields.test.ts src/objects/object-detail.test.tsx && pnpm typecheck && pnpm lint`. PASS — the object-detail tests must stay green (output-preserving refactor).
+
+- [ ] **Step 5: Commit**
+```bash
+git add web/src/lib/group-fields.ts web/src/lib/group-fields.test.ts web/src/objects/object-detail.tsx
+git commit -m "refactor(web): extract groupDefinitions helper; object-detail uses it (#45)"
+```
+
+---
+
+# Task 2: Group the object-form flexible inputs + test + gate
+
+**Files:** `web/src/objects/object-form.tsx`, `web/src/objects/object-form.test.tsx`.
+
+- [ ] **Step 1: Group the flexible block** in `object-form.tsx`. Add `import { groupDefinitions } from "../lib/group-fields";`. Replace the flexible `<fieldset>` body:
+```tsx
+{definitions && definitions.length > 0 && (
+  <fieldset className="space-y-3 border-t pt-3">
+    <legend className="sr-only">{t("form.flexibleHeading")}</legend>
+    {groupDefinitions(definitions, t("fields.other")).map((g) => (
+      <div key={g.group} className="space-y-3">
+        <div className="label-caption">{g.group}</div>
+        {g.defs.map((def) => (
+          <div key={def.key}>
+            <FieldInput definition={def} form={form} />
+            {errors.fields?.[def.key] && (
+              <p role="alert" className="text-xs text-destructive">
+                {errors.fields[def.key]?.message ?? t("form.required")}
+              </p>
+            )}
+          </div>
+        ))}
+      </div>
+    ))}
+  </fieldset>
+)}
+```
+  Change ONLY this block: the `<legend>` goes from visible `label-caption` to `sr-only`; the flat `definitions.map` becomes grouped. Field inputs + error markup are identical, just nested under group wrappers. No change anywhere else (core fields, visibility, footer, submit logic).
+
+- [ ] **Step 2: Test** — extend `object-form.test.tsx`. The field-def fixtures have `inscription` in group `"Description"` and the rest ungrouped → "Other". Add a test that renders `<ObjectForm mode="create" …>` and asserts the group subheadings + membership:
+```tsx
+test("groups flexible fields by definition group with subheadings", async () => {
+  renderApp(<ObjectForm mode="create" onSubmit={() => {}} onCancel={() => {}} />);
+  // the "Description" group heading and the "Other" group heading both render
+  expect(await screen.findByText("Description")).toBeInTheDocument();
+  expect(screen.getByText(/^Other$/)).toBeInTheDocument();
+  // the Description-grouped field input is present (Inscription) and appears before an ungrouped one (Material)
+  const inscription = screen.getByLabelText(/inscription/i);
+  const material = screen.getByLabelText(/material/i);
+  expect(inscription.compareDocumentPosition(material) & Node.DOCUMENT_POSITION_FOLLOWING).toBeTruthy();
+});
+```
+  (Adjust field labels to the fixtures' actual rendered labels — read `web/src/test/fixtures.ts` `fieldDefinitions` for the exact `labels`/keys and `web/src/objects/field-input.tsx` for how each renders its label, so the `getByLabelText`/`findByText` queries match. The key assertion: a named group heading + the "Other" heading both appear, and a grouped field precedes an ungrouped one in the DOM.) Keep the existing object-form tests green.
+
+- [ ] **Step 3: FULL GATE (run tests EXACTLY ONCE):**
+```bash
+cd web && pnpm typecheck && pnpm lint && pnpm test && pnpm build && pnpm check:size && pnpm check:colors
+```
+All green. Report test totals, largest chunk, check:colors line.
+
+- [ ] **Step 4: Codename + status:**
+```bash
+cd /Users/olsson/Laboratory/biggus-dickus
+git grep -in 'biggus\|dickus' -- web/src; echo "codename-exit=$?"
+git status --short
+```
+
+- [ ] **Step 5: Manual smoke (recommended).** `pnpm dev`: open New object / edit — the flexible fields now appear under group subheadings (e.g. "Description", "Other") matching the detail view's grouping; inputs/validation/submit still work.
+
+- [ ] **Step 6: Commit**
+```bash
+git add web/src/objects/object-form.tsx web/src/objects/object-form.test.tsx
+git commit -m "feat(web): group object-form flexible fields by definition group (#45)"
+```
+
+---
+
+## Self-Review (completed)
+
+**Spec coverage:** shared `groupDefinitions` + unit test (T1 S1–S2); detail refactor output-preserving (T1 S3–S4); form grouped via the helper with `sr-only` legend + visible subheadings (T2 S1); form grouping test (T2 S2); gate (T2 S3). Acceptance criteria 1–5 mapped. ✓
+
+**Placeholder scan:** the form test says "adjust labels to the fixtures' actual rendered labels" with the files named (fixtures.ts, field-input.tsx) — a concrete match-the-data step, not a TODO; the core assertion (named + Other headings, order) is explicit. The helper-test cast note keeps it `any`-free. No vague steps. ✓
+
+**Type/consistency:** `groupDefinitions(defs, otherLabel): FieldGroup[]` defined in T1, consumed by detail (`present`) and form (all `definitions`); detail's orphan-Other append stays last; the form reuses the existing `FieldInput`/error markup unchanged. ✓
+
+## Notes
+- No new dependency; no new i18n keys (`fields.other` + `form.flexibleHeading` exist).
+- The refactor of object-detail is output-preserving — its tests are the guard.
+- Field-list's A–Z grouping is intentionally NOT unified (different purpose).
diff --git a/docs/superpowers/specs/2026-06-08-form-field-grouping-design.md b/docs/superpowers/specs/2026-06-08-form-field-grouping-design.md
new file mode 100644
index 0000000..d31be7e
--- /dev/null
+++ b/docs/superpowers/specs/2026-06-08-form-field-grouping-design.md
@@ -0,0 +1,136 @@
+# Object-Form Flexible-Field Grouping — Design
+
+**Date:** 2026-06-08
+**Status:** Approved (brainstorming) — ready for implementation planning.
+**Issue:** #45 (deferred half — the object **form**'s flexible-field grouping; the detail view shipped in `e2ae093`).
+
+## Context
+
+#45 fixed the object **detail** view: flexible fields are now grouped by `FieldDefinitionView.group`
+in definition order with a trailing "Other" bucket (`object-detail.tsx`). The issue's problem #2
+explicitly says "detail **and** form", but the **form** still renders flexible-field inputs flat — one
+`<fieldset>` with a single "Catalogue fields" legend and `definitions.map(...)` (definition order, no
+group subheadings). This milestone brings the form to parity by reusing the *same* grouping the detail
+view uses (extracted into a shared helper so they can't drift).
+
+**Facts:** `object-detail.tsx:71-94` builds `{ group, defs }[]` inline: iterate the definitions
+(filtered to those with a value), bucket by `def.group?.trim()` else `t("fields.other")`, sort so the
+"Other" group is last, plus orphan-key handling. `object-form.tsx` renders the flexible block as
+`<fieldset className="space-y-3 border-t pt-3"><legend className="label-caption">{form.flexibleHeading}</legend>{definitions.map((def) => <div key={def.key}><FieldInput .../>{error}</div>)}</fieldset>`.
+Field-definition fixtures carry `group` (e.g. `"Description"` / `null`). `field-list.tsx` also groups,
+but A–Z (a management list, from #50) — out of scope to unify with it.
+
+### Decisions (from brainstorming)
+1. Extract the definition-grouping into a shared `lib/group-fields.ts` and use it in **both** detail
+   and form (one source of truth).
+2. The form keeps its `<fieldset>` for a11y but with an `sr-only` legend; visible per-group
+   `label-caption` subheadings (matching the detail view) — no redundant double-heading.
+3. Definition order within groups (no re-sort); ungrouped → trailing "Other".
+
+## Components
+
+### `web/src/lib/group-fields.ts` (new)
+```ts
+import type { components } from "../api/schema";
+
+type FieldDefinitionView = components["schemas"]["FieldDefinitionView"];
+
+export type FieldGroup = { group: string; defs: FieldDefinitionView[] };
+
+/** Group field definitions by `def.group` (trimmed), preserving definition order
+ *  within and across groups; ungrouped defs fall into a trailing `otherLabel` bucket. */
+export function groupDefinitions(
+  definitions: FieldDefinitionView[],
+  otherLabel: string,
+): FieldGroup[] {
+  const groups: FieldGroup[] = [];
+  for (const def of definitions) {
+    const group = def.group?.trim() ? def.group : otherLabel;
+    let bucket = groups.find((g) => g.group === group);
+    if (!bucket) {
+      bucket = { group, defs: [] };
+      groups.push(bucket);
+    }
+    bucket.defs.push(def);
+  }
+  // Keep definition order among real groups; the "Other" bucket sorts last.
+  groups.sort((a, b) => Number(a.group === otherLabel) - Number(b.group === otherLabel));
+  return groups;
+}
+```
+A unit test asserts: definition order preserved; two defs in the same group bucket together; ungrouped
+defs land in the `otherLabel` bucket which is **last** even when defined before a grouped def.
+
+### `object-detail.tsx` (refactor to the shared helper)
+Replace the inline `for (const def of present) { … }` group-building + final `groups.sort(...)` with
+`const groups = groupDefinitions(present, other);`. Keep the existing orphan handling appended after
+(`if (orphans.length > 0 && !groups.some(g => g.group === other)) groups.push({ group: other, defs: [] });`
+— appending the Other bucket still leaves it last). Render is unchanged. Net: identical output, now via
+the shared helper. (Verify the existing object-detail tests stay green.)
+
+### `object-form.tsx` (group the flexible inputs)
+Replace the flat flexible block with grouped rendering, reusing the FieldInput + per-field error markup
+inside each group:
+```tsx
+{definitions && definitions.length > 0 && (
+  <fieldset className="space-y-3 border-t pt-3">
+    <legend className="sr-only">{t("form.flexibleHeading")}</legend>
+    {groupDefinitions(definitions, t("fields.other")).map((g) => (
+      <div key={g.group} className="space-y-3">
+        <div className="label-caption">{g.group}</div>
+        {g.defs.map((def) => (
+          <div key={def.key}>
+            <FieldInput definition={def} form={form} />
+            {errors.fields?.[def.key] && (
+              <p role="alert" className="text-xs text-destructive">
+                {errors.fields[def.key]?.message ?? t("form.required")}
+              </p>
+            )}
+          </div>
+        ))}
+      </div>
+    ))}
+  </fieldset>
+)}
+```
+- The `<legend>` becomes `sr-only` (a11y-correct fieldset name) while the visible structure is the
+  per-group `label-caption` subheadings — mirroring detail, no double-heading.
+- Field inputs and their error rendering are unchanged (just moved under group wrappers); the submit
+  payload / validation / pruning are untouched (the same `definitions` drive the same inputs).
+- `import { groupDefinitions } from "../lib/group-fields";` (and `fields.other` is an existing key).
+
+## Data flow
+`useFieldDefinitions()` → `groupDefinitions(defs, t("fields.other"))` → grouped subheadings + the same
+`FieldInput`s. No change to form state, RHF registration, pruning, or submission.
+
+## Error handling / edges
+- Definition order preserved; "Other" last (even if an ungrouped def precedes a grouped one).
+- All-ungrouped case → a single "Other" group with a visible "Other" subheading (consistent with the
+  detail view's behavior).
+- The shared helper takes the caller's def list: detail passes `present` (defs with values); the form
+  passes all `definitions`. Orphan handling stays in detail only.
+- `sr-only` legend keeps the fieldset accessible without a visible redundant heading.
+
+## Testing
+- **`group-fields.test.ts`** (unit): order preserved; same-group bucketing; ungrouped → trailing Other.
+- **object-form test:** with the field-definition fixtures (which include `group` values + ungrouped),
+  rendering the form shows the grouped subheadings (e.g. "Description" then "Other") and the fields
+  under them in definition order. (Extend `object-form.test.tsx`; reuse the existing MSW field-def
+  handler / fixtures — add a `group` to one fixture def if needed to exercise a real named group.)
+- **object-detail tests** stay green (the refactor is output-preserving).
+- Gate: `typecheck`/`lint`/`test`/`build`/`check:size`/`check:colors`; no new i18n keys (reuse
+  `fields.other`, `form.flexibleHeading`); en/sv parity unaffected; no codename; no new dependency.
+
+## Acceptance criteria
+1. `groupDefinitions` exists (shared, unit-tested) and is used by **both** object-detail and object-form.
+2. The object form renders flexible-field inputs grouped by `def.group` (definition order, "Other" last)
+   with `label-caption` subheadings; the fieldset keeps an `sr-only` legend.
+3. The detail view's grouping is unchanged in output (now via the shared helper).
+4. Form behavior is otherwise unchanged (inputs, validation, errors, submission, pruning).
+5. `typecheck`/`lint`/`test`/`build`/`check:colors` green; `check:size` reported; en/sv parity; no
+   codename; no new dependency.
+
+## Out of scope → follow-ups
+- Export/PDF (#39); backend label resolution.
+- Reordering fields within a group beyond definition order; a field-definition "position"/sort concept.
+- Unifying `field-list.tsx`'s (A–Z) grouping with this (different purpose — a management list).
diff --git a/web/src/lib/group-fields.test.ts b/web/src/lib/group-fields.test.ts
new file mode 100644
index 0000000..e0c59f6
--- /dev/null
+++ b/web/src/lib/group-fields.test.ts
@@ -0,0 +1,40 @@
+import { expect, test } from "vitest";
+import { groupDefinitions } from "./group-fields";
+import type { components } from "../api/schema";
+
+type FieldDefinitionView = components["schemas"]["FieldDefinitionView"];
+type MinDef = Pick<FieldDefinitionView, "key" | "group">;
+
+const def = (key: string, group: string | null): MinDef => ({
+  key,
+  group: group as FieldDefinitionView["group"],
+});
+
+function keysByGroup(defs: MinDef[]) {
+  return groupDefinitions(defs as FieldDefinitionView[], "Other").map((g) => ({
+    group: g.group,
+    keys: g.defs.map((d) => d.key),
+  }));
+}
+
+test("preserves definition order within and across groups; Other is last", () => {
+  const result = keysByGroup([
+    def("a", "Description"),
+    def("b", null),
+    def("c", "Description"),
+    def("d", "Provenance"),
+    def("e", "  "),
+  ]);
+
+  expect(result).toEqual([
+    { group: "Description", keys: ["a", "c"] },
+    { group: "Provenance", keys: ["d"] },
+    { group: "Other", keys: ["b", "e"] },
+  ]);
+});
+
+test("all-ungrouped → a single trailing Other group", () => {
+  expect(keysByGroup([def("x", null), def("y", null)])).toEqual([
+    { group: "Other", keys: ["x", "y"] },
+  ]);
+});
diff --git a/web/src/lib/group-fields.ts b/web/src/lib/group-fields.ts
new file mode 100644
index 0000000..d7fb9f7
--- /dev/null
+++ b/web/src/lib/group-fields.ts
@@ -0,0 +1,30 @@
+import type { components } from "../api/schema";
+
+type FieldDefinitionView = components["schemas"]["FieldDefinitionView"];
+
+export type FieldGroup = { group: string; defs: FieldDefinitionView[] };
+
+/** Group field definitions by `def.group` (trimmed), preserving definition order
+ *  within and across groups; ungrouped defs fall into a trailing `otherLabel` bucket. */
+export function groupDefinitions(
+  definitions: FieldDefinitionView[],
+  otherLabel: string,
+): FieldGroup[] {
+  const groups: FieldGroup[] = [];
+
+  for (const def of definitions) {
+    const group = def.group?.trim() ? def.group : otherLabel;
+    let bucket = groups.find((g) => g.group === group);
+
+    if (!bucket) {
+      bucket = { group, defs: [] };
+      groups.push(bucket);
+    }
+
+    bucket.defs.push(def);
+  }
+
+  groups.sort((a, b) => Number(a.group === otherLabel) - Number(b.group === otherLabel));
+
+  return groups;
+}
diff --git a/web/src/objects/object-detail.tsx b/web/src/objects/object-detail.tsx
index 326d48f..de1aef6 100644
--- a/web/src/objects/object-detail.tsx
+++ b/web/src/objects/object-detail.tsx
@@ -4,6 +4,7 @@ import { useTranslation } from "react-i18next";
 
 import type { components } from "../api/schema";
 import { useObject, useFieldDefinitions } from "../api/queries";
+import { groupDefinitions } from "../lib/group-fields";
 import { formatDate } from "../lib/format-date";
 import { useDocumentTitle } from "../lib/use-document-title";
 import { useBreadcrumb } from "../shell/use-breadcrumb";
@@ -14,7 +15,6 @@ import { VisibilityBadge } from "./visibility-badge";
 import { buttonVariants } from "@/components/ui/button";
 import { Skeleton } from "@/components/ui/skeleton";
 
-type FieldDefinitionView = components["schemas"]["FieldDefinitionView"];
 type AdminObjectView = components["schemas"]["AdminObjectView"];
 
 function Field({ label, value }: { label: string; value: ReactNode }) {
@@ -70,17 +70,8 @@ function ObjectDetailLoaded({ object }: { object: AdminObjectView }) {
   // into a trailing "Other" group.
   const other = t("fields.other");
   const present = (definitions ?? []).filter((d) => object.fields[d.key] != null);
-  const groups: { group: string; defs: FieldDefinitionView[] }[] = [];
-  for (const def of present) {
-    const isOther = !def.group?.trim();
-    const group = isOther ? other : def.group!;
-    let bucket = groups.find((x) => x.group === group);
-    if (!bucket) {
-      bucket = { group, defs: [] };
-      groups.push(bucket);
-    }
-    bucket.defs.push(def);
-  }
+  const groups = groupDefinitions(present, other);
+
   // Defensive: a key present in object.fields with no matching definition (e.g. a
   // definition removed after the value was set). Render it muted under "Other"
   // rather than silently dropping data; the raw key is the label.
@@ -88,10 +79,10 @@ function ObjectDetailLoaded({ object }: { object: AdminObjectView }) {
   const orphans = Object.entries(object.fields).filter(
     ([key, value]) => !definedKeys.has(key) && value != null,
   );
+
   if (orphans.length > 0 && !groups.some((g) => g.group === other)) {
     groups.push({ group: other, defs: [] });
   }
-  groups.sort((a, b) => Number(a.group === other) - Number(b.group === other));
 
   return (
     <div className="overflow-auto p-4">
diff --git a/web/src/objects/object-form.test.tsx b/web/src/objects/object-form.test.tsx
index d12a4c1..b2fad57 100644
--- a/web/src/objects/object-form.test.tsx
+++ b/web/src/objects/object-form.test.tsx
@@ -82,6 +82,18 @@ test("edit mode: no visibility control, save button, prefilled values", async ()
   expect(screen.getByRole("button", { name: /save/i })).toBeInTheDocument();
 });
 
+test("groups flexible fields by definition group with subheadings", async () => {
+  renderApp(<ObjectForm mode="create" onSubmit={vi.fn()} onCancel={() => {}} />);
+
+  expect(await screen.findByText("Description")).toBeInTheDocument();
+  expect(screen.getByText(/^Other$/)).toBeInTheDocument();
+
+  const inscription = screen.getByLabelText(/inscription/i);
+  const material = screen.getByLabelText(/material/i);
+
+  expect(inscription.compareDocumentPosition(material) & Node.DOCUMENT_POSITION_FOLLOWING).toBeTruthy();
+});
+
 test("pruneFields: localized_text keeps only the default-language key, other object fields unaffected", () => {
   const localizedTextKeys = new Set(["title_ml"]);
 
diff --git a/web/src/objects/object-form.tsx b/web/src/objects/object-form.tsx
index 0e72c0b..418c11e 100644
--- a/web/src/objects/object-form.tsx
+++ b/web/src/objects/object-form.tsx
@@ -6,6 +6,7 @@ import { useFieldDefinitions } from "../api/queries";
 import { useConfig } from "../config/config-context";
 import { FieldInput } from "./field-input";
 import { pruneFields } from "./prune-fields";
+import { groupDefinitions } from "../lib/group-fields";
 import { UnsavedChangesDialog } from "../lib/unsaved-changes-dialog";
 import { useUnsavedChanges } from "../lib/use-unsaved-changes";
 import { Button } from "@/components/ui/button";
@@ -197,19 +198,23 @@ export function ObjectForm({
 
       {definitions && definitions.length > 0 && (
         <fieldset className="space-y-3 border-t pt-3">
-          <legend className="label-caption">
-            {t("form.flexibleHeading")}
-          </legend>
+          <legend className="sr-only">{t("form.flexibleHeading")}</legend>
 
-          {definitions.map((def) => (
-            <div key={def.key}>
-              <FieldInput definition={def} form={form} />
+          {groupDefinitions(definitions, t("fields.other")).map((g) => (
+            <div key={g.group} className="space-y-3">
+              <div className="label-caption">{g.group}</div>
 
-              {errors.fields?.[def.key] && (
-                <p role="alert" className="text-xs text-destructive">
-                  {errors.fields[def.key]?.message ?? t("form.required")}
-                </p>
-              )}
+              {g.defs.map((def) => (
+                <div key={def.key}>
+                  <FieldInput definition={def} form={form} />
+
+                  {errors.fields?.[def.key] && (
+                    <p role="alert" className="text-xs text-destructive">
+                      {errors.fields[def.key]?.message ?? t("form.required")}
+                    </p>
+                  )}
+                </div>
+              ))}
             </div>
           ))}
         </fieldset>