diff --git a/.changeset/bcf-topic-not-issue-terminology.md b/.changeset/bcf-topic-not-issue-terminology.md
new file mode 100644
index 0000000000..764dfeb301
--- /dev/null
+++ b/.changeset/bcf-topic-not-issue-terminology.md
@@ -0,0 +1,19 @@
+---
+"@ifc-lite/viewer": patch
+"@ifc-lite/bcf": patch
+"@ifc-lite/bcf-api": patch
+"@ifc-lite/sdk": patch
+"@ifc-lite/cli": patch
+"@ifc-lite/mcp": patch
+"@ifc-lite/sandbox": patch
+---
+
+Finish renaming the BCF "issues" language to "topics" across the app, docs, and package-facing text. Per the BCF-XML specification, `Topic` is the container element and `Issue` is only one `TopicType` value among several (Request, Comment, Error, Warning, Info); the previous patch fixed the BCF panel's own title, heading, empty-state copy, and topic-title placeholder, and left the rest of the product inconsistent.
+
+Remaining app-visible surfaces now fixed: the Analyze ribbon's "BCF issues" toggle button (a fourth site, alongside the command palette, main toolbar, and workspace-panel controls fixed previously), the compare panel's "Create BCF issue" affordance and "Issue for" header, the auto-created BCF project's default name (`<model>_Issues` → `<model>_Topics`, matching the BCF panel's own default), the landing-page hero animation's "Issue" step label, the MCP playground's BCF category blurb and example export path, and BCF-related copy across three in-app tours (`bcf`, `compare`, `clash`) — tour titles/descriptions plus five step titles/bodies.
+
+Docs updated to match: `docs/index.md`, `README.md`, `docs/guide/quickstart.md`, `docs/guide/bcf.md`, `docs/api/typescript.md`, and the CLI guide/reference's `bcf` examples (`--out topic.bcf`, `bcf list topics.bcf`), which also renamed the example filenames for consistency — they are illustrative only; the CLI has no default BCF filename.
+
+Also reworded now-inconsistent internal comments and JSDoc in the touched files, `@ifc-lite/bcf`'s package README and `createTopic` doc comment, `@ifc-lite/bcf-api`'s README, `@ifc-lite/sdk`'s `bim.bcf` namespace docs, `@ifc-lite/mcp`'s `bcf` tool docblock and fire-rating prompt template, and `@ifc-lite/sandbox`'s clash-to-BCF tool description — all comment/doc-only, no behavior change beyond the CLI's `bcf create` usage-message example (`--title "Issue"` → `--title "Missing door"`, matching the `--help` listing).
+
+Left deliberately unchanged: `bcfHelpers.tsx`'s `TOPIC_TYPES` list and every other real `TopicType` spec value (including the MCP `bcf` tool's `type` default and the sandbox playground's `topicType` default, both `'Issue'`), `ClashPanel`'s unrelated clash-detection "issues", GitHub issue-number references, and `registry.ts`'s `id: 'bcf'` panel key.
diff --git a/.claude/skills/use-ifclite/cli-reference.md b/.claude/skills/use-ifclite/cli-reference.md
index 2cda1daaff..83a91f59d1 100644
--- a/.claude/skills/use-ifclite/cli-reference.md
+++ b/.claude/skills/use-ifclite/cli-reference.md
@@ -91,9 +91,9 @@ Flags: `--json` · `--locale en|de|fr`. Exit 0 (pass) / 1 (fail).
 ## bcf
 
 ```bash
-ifc-lite bcf create --title "Missing fire door" --description "Level 2" --out issue.bcf
-ifc-lite bcf list issues.bcf
-ifc-lite bcf add-comment --file issues.bcf --text "Fixed in rev 3" --out updated.bcf
+ifc-lite bcf create --title "Missing fire door" --description "Level 2" --out topic.bcf
+ifc-lite bcf list topics.bcf
+ifc-lite bcf add-comment --file topics.bcf --text "Fixed in rev 3" --out updated.bcf
 ```
 
 ## create
diff --git a/README.md b/README.md
index 0eaaa4ab4c..ddcb90a89f 100644
--- a/README.md
+++ b/README.md
@@ -243,7 +243,7 @@ Not sure? Start with the browser setup. You can add a server or switch engines l
 | Export to glTF / IFC / Parquet | + `@ifc-lite/export` |
 | Detect clashes | + `@ifc-lite/clash` |
 | Diff two model versions | + `@ifc-lite/diff` |
-| BCF issue tracking | + `@ifc-lite/bcf` |
+| BCF topic tracking | + `@ifc-lite/bcf` |
 | Filter and colorize in 3D by rules | + `@ifc-lite/lens` |
 | Build schedules and property tables | + `@ifc-lite/lists` |
 | Script models with the `bim.*` API | + `@ifc-lite/sdk` |
diff --git a/apps/viewer/src/components/mcp/HeroScene.tsx b/apps/viewer/src/components/mcp/HeroScene.tsx
index b02ff05285..5b11ed2e1d 100644
--- a/apps/viewer/src/components/mcp/HeroScene.tsx
+++ b/apps/viewer/src/components/mcp/HeroScene.tsx
@@ -78,7 +78,7 @@ export const HERO_STEPS: HeroStep[] = [
   { verb: 'Standardize', line: 'bsdd_property_sets("IfcWall")',                family: 'bSDD',      overlay: { kind: 'psets', psets: ['Pset_WallCommon', 'Qto_WallBaseQuantities', 'Pset_ConcreteElementGeneral'] } },
   { verb: 'Add',       line: 'entity_create(IfcDoor)',                         family: 'Mutation' },
   { verb: 'Section',   line: 'viewer_set_section(z = 2.2)',                    family: 'Viewer' },
-  { verb: 'Issue',     line: 'bcf_topic_create("missing fire rating")',        family: 'BCF',       overlay: { kind: 'pin', ref: 'BCF #04' } },
+  { verb: 'Flag',      line: 'bcf_topic_create("missing fire rating")',        family: 'BCF',       overlay: { kind: 'pin', ref: 'BCF #04' } },
   { verb: 'Inspect',   line: 'viewer_describe_selection()',                    family: 'Viewer',    overlay: { kind: 'card', ref: 'IfcWall #262', lines: ['Pset_WallCommon · IsExternal=true', 'FireRating=EI60 · 240 mm concrete'] } },
 ];
 
diff --git a/apps/viewer/src/components/mcp/data.ts b/apps/viewer/src/components/mcp/data.ts
index d7dcd50a9a..65ea8f37ac 100644
--- a/apps/viewer/src/components/mcp/data.ts
+++ b/apps/viewer/src/components/mcp/data.ts
@@ -63,7 +63,7 @@ export const CATEGORY_BLURBS: Record<ToolCategory, string> = {
   Geometry: 'Bounding boxes, volumes, areas — read from quantity sets.',
   Validation: 'IDS specs and a built-in model audit.',
   Mutation: 'Queue property/attribute writes; persist on save.',
-  BCF: 'Author and export buildingSMART issues + viewpoints.',
+  BCF: 'Author and export buildingSMART topics + viewpoints.',
   bSDD: 'Look up canonical class/property metadata.',
   Diff: 'Compare two loaded models — added/removed/changed.',
   Export: 'Dump to .ifc, CSV, JSON, glTF, IFCx, PDF.',
@@ -618,7 +618,7 @@ export const EXAMPLES: Record<string, Record<string, unknown>> = {
   bcf_topic_update: { guid: '7e87d7f4-...', comment: 'Confirmed with the structural team.' },
   bcf_topic_close: { guid: '7e87d7f4-...' },
   bcf_viewpoint_create: { guid: '7e87d7f4-...', selection_global_ids: ['1AQAupaRP1txwK1AGiN61V'] },
-  bcf_export: { file_path: '/tmp/issues.bcfzip' },
+  bcf_export: { file_path: '/tmp/topics.bcfzip' },
   bsdd_search: { query: 'wall' },
   bsdd_class: { ifc_type: 'IfcWall' },
   bsdd_property_sets: { ifc_type: 'IfcWall' },
diff --git a/apps/viewer/src/components/mcp/playground-dispatcher.ts b/apps/viewer/src/components/mcp/playground-dispatcher.ts
index a85966a2e5..043c1be2fb 100644
--- a/apps/viewer/src/components/mcp/playground-dispatcher.ts
+++ b/apps/viewer/src/components/mcp/playground-dispatcher.ts
@@ -187,7 +187,7 @@ async function autoStageBcfDownload(): Promise<NonNullable<ToolDispatchResult['d
   const blob = await writeBCF(project);
   // Drop the previous staged copy so the panel only ever shows the latest.
   if (stagedBcfFileId) playgroundFiles.remove(stagedBcfFileId);
-  const filename = coerceFilename(undefined, 'bcfzip', 'issues');
+  const filename = coerceFilename(undefined, 'bcfzip', 'topics');
   const file = playgroundFiles.add({
     filename,
     mimeType: 'application/zip',
@@ -1120,7 +1120,7 @@ const IMPLS: Record<string, ToolImpl> = {
   },
   async bcf_export(_m, args) {
     const project = getBcfProject();
-    const filename = coerceFilename(args.file_path as string | undefined, 'bcfzip', 'issues');
+    const filename = coerceFilename(args.file_path as string | undefined, 'bcfzip', 'topics');
     const blob = await writeBCF(project);
     const file = playgroundFiles.add({
       filename, mimeType: 'application/zip', size: blob.size, blob,
@@ -1766,7 +1766,7 @@ function resolveIdsXml(args: Record<string, unknown>): string | null {
  *
  *   coerceFilename('wall_fire_rating.ids', 'ifc')   → 'wall_fire_rating.ifc'
  *   coerceFilename('/tmp/foo.bar/baz.csv', 'json')  → 'baz.json'
- *   coerceFilename(undefined, 'bcfzip', 'issues')   → 'issues.bcfzip'
+ *   coerceFilename(undefined, 'bcfzip', 'topics')   → 'topics.bcfzip'
  */
 function coerceFilename(
   raw: string | undefined,
diff --git a/apps/viewer/src/components/viewer/BCFPanel.tsx b/apps/viewer/src/components/viewer/BCFPanel.tsx
index 5cbb2f5455..31ee7ea0b4 100644
--- a/apps/viewer/src/components/viewer/BCFPanel.tsx
+++ b/apps/viewer/src/components/viewer/BCFPanel.tsx
@@ -3,7 +3,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 /**
- * BCFPanel - BIM Collaboration Format issue management panel
+ * BCFPanel - BIM Collaboration Format topic management panel
  *
  * Provides:
  * - Topic list with filtering
@@ -121,15 +121,15 @@ export function BCFPanel({ onClose }: BCFPanelProps) {
     if (models.size === 0) {
       // No models loaded, use date-based name
       const date = new Date().toISOString().split('T')[0];
-      return `BCF_Issues_${date}`;
+      return `BCF_Topics_${date}`;
     }
-    // Use first model's name (without extension) + "_Issues"
+    // Use first model's name (without extension) + "_Topics"
     const firstModel = models.values().next().value;
     if (firstModel?.name) {
       const baseName = firstModel.name.replace(/\.(ifc|ifczip)$/i, '');
-      return `${baseName}_Issues`;
+      return `${baseName}_Topics`;
     }
-    return `BCF_Issues_${new Date().toISOString().split('T')[0]}`;
+    return `BCF_Topics_${new Date().toISOString().split('T')[0]}`;
   }, [models]);
 
   // Initialize project if needed
@@ -194,7 +194,7 @@ export function BCFPanel({ onClose }: BCFPanelProps) {
       setBcfLoading(true);
       const blob = await writeBCF(bcfProject);
       // Use project name, or generate from model name, or date-based fallback
-      const fileName = sanitizeFilename(bcfProject.name || getDefaultProjectName(), { fallback: 'issues' });
+      const fileName = sanitizeFilename(bcfProject.name || getDefaultProjectName(), { fallback: 'topics' });
       downloadBlob(blob, `${fileName}.bcfzip`);
       posthog.capture('bcf_exported', { topic_count: bcfProject.topics.size });
     } catch (error) {
@@ -383,7 +383,7 @@ export function BCFPanel({ onClose }: BCFPanelProps) {
       <div className="flex items-center justify-between px-3 py-2 border-b border-border">
         <div className="flex items-center gap-2">
           <MessageSquare className="h-4 w-4" />
-          <h2 className="font-medium text-sm">BCF Issues</h2>
+          <h2 className="font-medium text-sm">BCF Topics</h2>
           {topics.length > 0 && (
             <Badge variant="secondary" className="text-xs">
               {topics.length}
diff --git a/apps/viewer/src/components/viewer/CommandPalette.tsx b/apps/viewer/src/components/viewer/CommandPalette.tsx
index 94cc480288..ad110f5ea1 100644
--- a/apps/viewer/src/components/viewer/CommandPalette.tsx
+++ b/apps/viewer/src/components/viewer/CommandPalette.tsx
@@ -354,7 +354,7 @@ export function CommandPalette({ open, onOpenChange }: CommandPaletteProps) {
         action: () => { const s = useViewerStore.getState(); s.setLeftPanelCollapsed(!s.leftPanelCollapsed); } },
       { id: 'panel:script', label: 'Script Editor', keywords: 'code automation console', category: 'Panels', icon: FileCode2,
         action: () => { activateBottomPanel('script'); } },
-      { id: 'panel:bcf', label: 'BCF Issues', keywords: 'collaboration topics comments viewpoint', category: 'Panels', icon: MessageSquare,
+      { id: 'panel:bcf', label: 'BCF Topics', keywords: 'collaboration topics comments viewpoint', category: 'Panels', icon: MessageSquare,
         action: () => { activateRightPanel('bcf'); } },
       { id: 'panel:ids', label: 'IDS Validation', keywords: 'information delivery specification check', category: 'Panels', icon: ClipboardCheck,
         action: () => { activateRightPanel('ids'); } },
diff --git a/apps/viewer/src/components/viewer/ComparePanel.tsx b/apps/viewer/src/components/viewer/ComparePanel.tsx
index f6ea17c9e0..da909d6dbc 100644
--- a/apps/viewer/src/components/viewer/ComparePanel.tsx
+++ b/apps/viewer/src/components/viewer/ComparePanel.tsx
@@ -232,7 +232,7 @@ export function ComparePanel({ onClose }: ComparePanelProps) {
     });
   };
 
-  // Composing a BCF issue: collapse the diff chrome so the form owns the panel.
+  // Composing a BCF topic: collapse the diff chrome so the form owns the panel.
   // Gate on the selected row too, so a vanished selection can never leave the
   // panel empty (chrome hidden but no form to show).
   const bcfComposing = bcf.formOpen && !!selectedRow;
@@ -265,8 +265,8 @@ export function ComparePanel({ onClose }: ComparePanelProps) {
       ) : (
         <>
           {/* Diff chrome (run controls, counts, report, results, detail) — hidden
-              while composing a BCF issue so the form owns the panel. The user has
-              committed to raising an issue and the change context is already in the
+              while composing a BCF topic so the form owns the panel. The user has
+              committed to raising a topic and the change context is already in the
               pre-filled form, so re-running / exports / browsing only get in the way. */}
           {!bcfComposing && (
             <>
@@ -378,7 +378,7 @@ export function ComparePanel({ onClose }: ComparePanelProps) {
               >
                 <ChevronLeft className="h-4 w-4" />
               </button>
-              <span className="text-muted-foreground shrink-0">Issue for</span>
+              <span className="text-muted-foreground shrink-0">Topic for</span>
               <span className="font-medium truncate min-w-0">{selectedRow.name || selectedRow.ifcType}</span>
               <span className="ml-auto text-[10px] text-muted-foreground shrink-0">
                 {selectedRow.ifcType.replace(/^Ifc/, '')}
@@ -386,7 +386,7 @@ export function ComparePanel({ onClose }: ComparePanelProps) {
             </div>
           )}
 
-          {/* Raise a BCF issue from the focused change (#1199) */}
+          {/* Raise a BCF topic from the focused change (#1199) */}
           {selectedRow && (
             <BcfFromChange
               row={selectedRow}
diff --git a/apps/viewer/src/components/viewer/MainToolbar.tsx b/apps/viewer/src/components/viewer/MainToolbar.tsx
index 7d5a13d760..c53bed247f 100644
--- a/apps/viewer/src/components/viewer/MainToolbar.tsx
+++ b/apps/viewer/src/components/viewer/MainToolbar.tsx
@@ -588,7 +588,7 @@ export function MainToolbar({ onShowShortcuts }: MainToolbarProps = {} as MainTo
             onCheckedChange={() => handleToggleRightPanel('bcf')}
           >
             <MessageSquare className="h-4 w-4 mr-2" />
-            BCF Issues
+            BCF Topics
           </DropdownMenuCheckboxItem>
           <DropdownMenuCheckboxItem
             checked={activeWorkspacePanels.has('ids')}
diff --git a/apps/viewer/src/components/viewer/bcf/BCFCreateTopicForm.tsx b/apps/viewer/src/components/viewer/bcf/BCFCreateTopicForm.tsx
index d72379c00c..a30433fd97 100644
--- a/apps/viewer/src/components/viewer/bcf/BCFCreateTopicForm.tsx
+++ b/apps/viewer/src/components/viewer/bcf/BCFCreateTopicForm.tsx
@@ -37,7 +37,7 @@ export interface BCFCreateTopicFormProps {
   onSubmit: (topic: Partial<BCFTopic>, options?: { includeSnapshot: boolean }) => void;
   onCancel: () => void;
   author: string;
-  /** Pre-fill the title (e.g. when raising an issue from a detected change). */
+  /** Pre-fill the title (e.g. when raising a topic from a detected change). */
   initialTitle?: string;
   /** Pre-fill the description. */
   initialDescription?: string;
@@ -141,7 +141,7 @@ export function BCFCreateTopicForm({
           id="title"
           value={title}
           onChange={(e) => setTitle(e.target.value)}
-          placeholder="Brief description of the issue"
+          placeholder="Brief description of the topic"
           required
         />
       </div>
diff --git a/apps/viewer/src/components/viewer/bcf/BCFTopicList.tsx b/apps/viewer/src/components/viewer/bcf/BCFTopicList.tsx
index abef54ca44..576c96e0c4 100644
--- a/apps/viewer/src/components/viewer/bcf/BCFTopicList.tsx
+++ b/apps/viewer/src/components/viewer/bcf/BCFTopicList.tsx
@@ -186,7 +186,7 @@ export function BCFTopicList({
               </div>
               {isDefaultEmail && !editingEmail && (
                 <p className="text-xs text-muted-foreground mt-2 text-center">
-                  Set your email to identify your issues and comments
+                  Set your email to identify your topics and comments
                 </p>
               )}
             </div>
diff --git a/apps/viewer/src/components/viewer/compare/BcfFromChange.tsx b/apps/viewer/src/components/viewer/compare/BcfFromChange.tsx
index 96f8dd4617..2a77509d6b 100644
--- a/apps/viewer/src/components/viewer/compare/BcfFromChange.tsx
+++ b/apps/viewer/src/components/viewer/compare/BcfFromChange.tsx
@@ -3,7 +3,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 /**
- * "Create BCF issue" affordance shown under the focused change (issue #1199).
+ * "Create BCF topic" affordance shown under the focused change (issue #1199).
  * Extracted from ComparePanel; the actual topic creation lives in the panel so
  * it can coordinate the BCF store + viewpoint capture.
  */
@@ -54,7 +54,7 @@ export function BcfFromChange({
     return (
       <div className="border-t border-border shrink-0 px-3 py-2.5 flex items-center gap-2 text-xs">
         <CheckCircle2 className="h-4 w-4 text-[#9ece6a] shrink-0" />
-        <span className="min-w-0 truncate">BCF issue created: “{createdTitle}”</span>
+        <span className="min-w-0 truncate">BCF topic created: “{createdTitle}”</span>
         <Button variant="outline" size="sm" className="ml-auto h-7 px-2 text-xs shrink-0" onClick={onOpenBcfPanel}>
           Open BCF
         </Button>
@@ -63,7 +63,7 @@ export function BcfFromChange({
   }
 
   if (open) {
-    // Composing a BCF issue: the diff chrome is collapsed (ComparePanel), so the
+    // Composing a BCF topic: the diff chrome is collapsed (ComparePanel), so the
     // form owns the remaining height and scrolls internally — its actions stay
     // reachable instead of being clipped off the bottom of the panel.
     return (
@@ -86,7 +86,7 @@ export function BcfFromChange({
     <div className="border-t border-border shrink-0 px-3 py-2.5">
       <Button variant="outline" size="sm" className="w-full gap-1.5 text-xs" onClick={onStart}>
         <MessageSquarePlus className="h-3.5 w-3.5" />
-        Create BCF issue
+        Create BCF topic
       </Button>
     </div>
   );
diff --git a/apps/viewer/src/components/viewer/compare/useBcfFromChange.ts b/apps/viewer/src/components/viewer/compare/useBcfFromChange.ts
index 878874e26e..97530e2375 100644
--- a/apps/viewer/src/components/viewer/compare/useBcfFromChange.ts
+++ b/apps/viewer/src/components/viewer/compare/useBcfFromChange.ts
@@ -3,7 +3,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 /**
- * Coordinates the "raise a BCF issue from a detected change" flow (#1199),
+ * Coordinates the "raise a BCF topic from a detected change" flow (#1199),
  * extracted from ComparePanel to keep it under the module-size house rule.
  *
  * Owns the create-form open/created state, captures a viewpoint (camera +
@@ -91,7 +91,7 @@ export function useBcfFromChange(
         const state = useViewerStore.getState();
         if (!state.bcfProject) {
           const first = modelList[0]?.name?.replace(/\.(ifc|ifczip)$/i, '') || 'Comparison';
-          state.setBcfProject(createBCFProject({ name: `${first}_Issues` }));
+          state.setBcfProject(createBCFProject({ name: `${first}_Topics` }));
         }
         // Resolve the viewpoint first so the topic's source-file Header can be
         // derived from the models its selection references before it is stored.
@@ -128,7 +128,7 @@ export function useBcfFromChange(
         setFormOpen(false);
         setCreatedTitle(topic.title);
       } catch (error) {
-        console.error('[compare] failed to create BCF issue from change', error);
+        console.error('[compare] failed to create BCF topic from change', error);
       } finally {
         submitInFlight.current = false;
       }
diff --git a/apps/viewer/src/components/viewer/ribbon/tabs/AnalyzeTab.test.tsx b/apps/viewer/src/components/viewer/ribbon/tabs/AnalyzeTab.test.tsx
new file mode 100644
index 0000000000..fda940633f
--- /dev/null
+++ b/apps/viewer/src/components/viewer/ribbon/tabs/AnalyzeTab.test.tsx
@@ -0,0 +1,38 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+/**
+ * The Analyze ribbon tab's "Validate" group has its own toggle button for
+ * the BCF panel — a fourth site (alongside CommandPalette, MainToolbar, and
+ * useWorkspacePanelControls, all pinned elsewhere) that once read "BCF
+ * issues". Topic is the BCF-XML container element and Issue is only one
+ * TopicType value among several (Request, Comment, Error, Warning, Info),
+ * so "issues" narrowed and contradicted the spec (#4096/#4097). Pin the
+ * corrected label here too, so it can't regress silently.
+ */
+
+import '@/test/setup-dom.js';
+import { afterEach, describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import { render, cleanup } from '@/test/render.js';
+import { AnalyzeTab } from './AnalyzeTab.js';
+
+describe('AnalyzeTab — BCF ribbon button', () => {
+  afterEach(() => {
+    cleanup();
+  });
+
+  it('labels the Validate-group BCF button "BCF topics", not "BCF issues"', () => {
+    const container = render(<AnalyzeTab />);
+    const labels = [...container.querySelectorAll('button')].map((b) => b.textContent ?? '');
+    assert.ok(
+      labels.some((t) => /BCF topics/.test(t)),
+      `expected a button labelled "BCF topics"; got: ${JSON.stringify(labels)}`,
+    );
+    assert.ok(
+      !labels.some((t) => /BCF issues/i.test(t)),
+      `found a button still labelled "BCF issues": ${JSON.stringify(labels)}`,
+    );
+  });
+});
diff --git a/apps/viewer/src/components/viewer/ribbon/tabs/AnalyzeTab.tsx b/apps/viewer/src/components/viewer/ribbon/tabs/AnalyzeTab.tsx
index 84afcfeb22..da1dbee2c7 100644
--- a/apps/viewer/src/components/viewer/ribbon/tabs/AnalyzeTab.tsx
+++ b/apps/viewer/src/components/viewer/ribbon/tabs/AnalyzeTab.tsx
@@ -45,7 +45,7 @@ export function AnalyzeTab() {
       <RibbonGroup label="Validate">
         <RibbonLargeButton
           icon={Issue}
-          label="BCF issues"
+          label="BCF topics"
           active={activeWorkspacePanels.has('bcf')}
           onClick={() => handleToggleRightPanel('bcf')}
         />
diff --git a/apps/viewer/src/components/viewer/toolbar/useWorkspacePanelControls.ts b/apps/viewer/src/components/viewer/toolbar/useWorkspacePanelControls.ts
index 285d18eaf1..7ea42f515a 100644
--- a/apps/viewer/src/components/viewer/toolbar/useWorkspacePanelControls.ts
+++ b/apps/viewer/src/components/viewer/toolbar/useWorkspacePanelControls.ts
@@ -276,7 +276,7 @@ export function useWorkspacePanelControls() {
     if (activeWorkspacePanels.has('script')) return 'Script Editor';
     if (activeWorkspacePanels.has('lists')) return 'Lists';
     if (activeWorkspacePanels.has('gantt')) return 'Schedule';
-    if (activeWorkspacePanels.has('bcf')) return 'BCF Issues';
+    if (activeWorkspacePanels.has('bcf')) return 'BCF Topics';
     if (activeWorkspacePanels.has('ids')) return 'IDS Validation';
     if (activeWorkspacePanels.has('lens')) return 'Lens Rules';
     if (activeWorkspacePanels.has('clash')) return 'Clash Detection';
diff --git a/apps/viewer/src/lib/panels/registry.test.ts b/apps/viewer/src/lib/panels/registry.test.ts
index 72200e5352..6463695ced 100644
--- a/apps/viewer/src/lib/panels/registry.test.ts
+++ b/apps/viewer/src/lib/panels/registry.test.ts
@@ -69,6 +69,18 @@ describe('workspacePanelForShortcutCode (Alt+digit routing #1200/#1208)', () =>
   });
 });
 
+// The BCF panel's title once read "BCF issues" — Topic is the BCF-XML
+// element and Issue is only one TopicType value among several (Request,
+// Comment, Error, Warning, Info), so "issues" narrowed and contradicted the
+// spec (#4096). Pin the corrected label so it can't regress silently.
+describe('BCF panel title', () => {
+  it('says "BCF topics", not "BCF issues" (#4096)', () => {
+    const bcf = WORKSPACE_PANELS.find((p) => p.id === 'bcf');
+    assert.ok(bcf, 'expected a bcf panel entry in the registry');
+    assert.strictEqual(bcf.title, 'BCF topics');
+  });
+});
+
 // `isBottomPanel` gates `usePanelControls`' toggle routing (script / gantt /
 // lists go through `toggleBottomPanel`, everything else through the sidebar
 // dock). The test above only exercises 'script' (Digit8) and 'lists'
diff --git a/apps/viewer/src/lib/panels/registry.ts b/apps/viewer/src/lib/panels/registry.ts
index 37cb595c72..e5e956c13d 100644
--- a/apps/viewer/src/lib/panels/registry.ts
+++ b/apps/viewer/src/lib/panels/registry.ts
@@ -86,7 +86,7 @@ export const WORKSPACE_PANELS: readonly WorkspacePanelDef[] = [
   // Alt+1..9 / Alt+0 — order frozen since #1200 for the first seven.
   { id: 'properties', title: 'Information', short: 'Info', Icon: Info, group: 'inspect', region: 'side' },
   { id: 'compare', title: 'Compare models', short: 'Compare', Icon: GitCompareArrows, group: 'inspect', region: 'side' },
-  { id: 'bcf', title: 'BCF issues', short: 'BCF', Icon: MessageSquare, group: 'review', region: 'side' },
+  { id: 'bcf', title: 'BCF topics', short: 'BCF', Icon: MessageSquare, group: 'review', region: 'side' },
   { id: 'ids', title: 'IDS validation', short: 'IDS', Icon: ClipboardCheck, group: 'review', region: 'side' },
   { id: 'lens', title: 'Lens rules', short: 'Lens', Icon: Palette, group: 'review', region: 'side' },
   { id: 'clash', title: 'Clash detection', short: 'Clash', Icon: Crosshair, group: 'review', region: 'side' },
diff --git a/apps/viewer/src/lib/tours/tours/bcf.ts b/apps/viewer/src/lib/tours/tours/bcf.ts
index ef4462c2c7..b64478a174 100644
--- a/apps/viewer/src/lib/tours/tours/bcf.ts
+++ b/apps/viewer/src/lib/tours/tours/bcf.ts
@@ -15,7 +15,7 @@ import type { TourDefinition } from '../types';
 
 export const BCF_TOUR: TourDefinition = {
   id: 'bcf',
-  title: 'Raise issues with BCF',
+  title: 'Raise topics with BCF',
   description: 'Flag a problem, capture viewpoints, and export a .bcfzip your whole team can open.',
   minutes: 3,
   version: 1,
@@ -27,15 +27,15 @@ export const BCF_TOUR: TourDefinition = {
       kind: 'action',
       anchor: activityAnchor('bcf'),
       placement: 'left',
-      title: 'Open BCF issues',
-      body: 'BCF is the open format for sharing issues between BIM tools. Open the BCF panel from the sidebar rail, or press Alt+3.',
+      title: 'Open BCF topics',
+      body: 'BCF is the open format for sharing topics between BIM tools. Open the BCF panel from the sidebar rail, or press Alt+3.',
       gate: { predicate: (s) => s.bcfPanelVisible },
     },
     {
       id: 'frame-problem',
       kind: 'canvas',
       title: 'Frame the problem',
-      body: 'Click an element to select it and orbit so the issue is in view. The viewpoint you capture next records this selection with the camera.',
+      body: 'Click an element to select it and orbit so the topic is in view. The viewpoint you capture next records this selection with the camera.',
       // A stale selection must not auto-advance the step (same guard as the
       // welcome tour's select step).
       prepare: (store) => {
@@ -50,7 +50,7 @@ export const BCF_TOUR: TourDefinition = {
       anchor: TOUR_ANCHORS.bcfNewTopic,
       panel: 'bcf',
       placement: 'left',
-      title: 'Create an issue',
+      title: 'Create a topic',
       body: 'Click +, give the topic a short title, and click Create Topic. A snapshot of your current view is attached automatically.',
       arm: (state, ctx) => {
         ctx.baseline.topics = state.bcfProject ? state.bcfProject.topics.size : 0;
diff --git a/apps/viewer/src/lib/tours/tours/clash.ts b/apps/viewer/src/lib/tours/tours/clash.ts
index 15b09dde96..651cb2e74b 100644
--- a/apps/viewer/src/lib/tours/tours/clash.ts
+++ b/apps/viewer/src/lib/tours/tours/clash.ts
@@ -31,7 +31,7 @@ let hadClashResultAtTourStart = 0;
 export const CLASH_TOUR: TourDefinition = {
   id: 'clash',
   title: 'Find clashes',
-  description: 'Detect overlapping elements, zoom to a clash, and hand it off as a BCF issue.',
+  description: 'Detect overlapping elements, zoom to a clash, and hand it off as a BCF topic.',
   minutes: 4,
   version: 1,
   panel: 'clash',
@@ -146,7 +146,7 @@ export const CLASH_TOUR: TourDefinition = {
       panel: 'clash',
       placement: 'left',
       title: 'Hand it off',
-      body: 'BCF topic files the focused clash as an issue with a snapshot. Clear removes the highlights when you are done.',
+      body: 'BCF topic files the focused clash with a snapshot. Clear removes the highlights when you are done.',
     },
   ],
 };
diff --git a/apps/viewer/src/lib/tours/tours/compare.ts b/apps/viewer/src/lib/tours/tours/compare.ts
index 4ce6e705c1..6acc2ceb5f 100644
--- a/apps/viewer/src/lib/tours/tours/compare.ts
+++ b/apps/viewer/src/lib/tours/tours/compare.ts
@@ -113,7 +113,7 @@ export const COMPARE_TOUR: TourDefinition = {
       panel: 'compare',
       placement: 'left',
       title: 'See exactly what changed',
-      body: 'The detail lists before and after values; a moved element shows its Moved distance. Export a report or raise a BCF issue from here.',
+      body: 'The detail lists before and after values; a moved element shows its Moved distance. Export a report or raise a BCF topic from here.',
     },
   ],
 };
diff --git a/apps/viewer/src/store/slices/bcfSlice.ts b/apps/viewer/src/store/slices/bcfSlice.ts
index 387787a3ab..9a5d0df319 100644
--- a/apps/viewer/src/store/slices/bcfSlice.ts
+++ b/apps/viewer/src/store/slices/bcfSlice.ts
@@ -5,7 +5,7 @@
 /**
  * BCF (BIM Collaboration Format) state slice
  *
- * Manages BCF topics, comments, and viewpoints for issue tracking.
+ * Manages BCF topics, comments, and viewpoints.
  */
 
 import type { StateCreator } from 'zustand';
diff --git a/docs/api/typescript.md b/docs/api/typescript.md
index fb1ca15b82..cf8b5bc20d 100644
--- a/docs/api/typescript.md
+++ b/docs/api/typescript.md
@@ -829,7 +829,7 @@ For byte-reproducible **exported files**, seed the exporter too: builders that a
 
 ## @ifc-lite/bcf
 
-BCF (BIM Collaboration Format) support for issue tracking. Implements BCF 2.1 and 3.0.
+BCF (BIM Collaboration Format) support for topic tracking. Implements BCF 2.1 and 3.0.
 
 ### readBCF / writeBCF
 
diff --git a/docs/guide/bcf.md b/docs/guide/bcf.md
index b9564be8f5..c111586c6f 100644
--- a/docs/guide/bcf.md
+++ b/docs/guide/bcf.md
@@ -1,13 +1,13 @@
 # BCF Collaboration
 
-IFClite supports **BCF (BIM Collaboration Format)**, the buildingSMART standard for issue tracking in BIM projects. The `@ifc-lite/bcf` package implements BCF 2.1 and 3.0 specifications.
+IFClite supports **BCF (BIM Collaboration Format)**, the buildingSMART standard for topic tracking in BIM projects. The `@ifc-lite/bcf` package implements BCF 2.1 and 3.0 specifications.
 
 ## What is BCF?
 
-BCF allows teams to create, share, and manage issues (called **topics**) linked to specific locations and components in a BIM model. Each topic can include:
+BCF allows teams to create, share, and manage **topics** linked to specific locations and components in a BIM model. Each topic can optionally be typed (Issue, Request, Comment, and more) and can include:
 
 - **Viewpoints** - Camera positions and component visibility snapshots
-- **Comments** - Discussion threads on the issue
+- **Comments** - Discussion threads on the topic
 - **Component references** - Links to specific IFC entities via GlobalId
 
 ## Quick Start
@@ -72,7 +72,7 @@ const bcfBlob = await writeBCF(project);
 
 ## Viewpoints
 
-Viewpoints capture the camera state and component visibility at the time an issue is created. IFClite provides utilities to convert between viewer camera state and BCF viewpoint format.
+Viewpoints capture the camera state and component visibility at the time a topic is created. IFClite provides utilities to convert between viewer camera state and BCF viewpoint format.
 
 ### Creating Viewpoints
 
@@ -233,7 +233,7 @@ In the IFClite viewer, BCF is integrated through the BCF panel:
 | Type | Description |
 |------|-------------|
 | `BCFProject` | Top-level container with topics map and version |
-| `BCFTopic` | An issue with title, status, comments, and viewpoints |
+| `BCFTopic` | A topic with title, status, comments, and viewpoints |
 | `BCFComment` | A comment on a topic with author and timestamp |
 | `BCFViewpoint` | Camera state, component visibility, and clipping planes |
 | `BCFComponents` | Selected, visible, and colored component references |
diff --git a/docs/guide/cli.md b/docs/guide/cli.md
index f4926ad6a2..e64bf25644 100644
--- a/docs/guide/cli.md
+++ b/docs/guide/cli.md
@@ -588,14 +588,14 @@ Returns pass/fail summary with exit code 0 (pass) or 1 (fail).
 Create, read, and manage BCF (BIM Collaboration Format) files.
 
 ```bash
-# Create a new BCF issue
-ifc-lite bcf create --title "Missing fire door" --description "Level 2, Room 201" --out issue.bcf
+# Create a new BCF topic
+ifc-lite bcf create --title "Missing fire door" --description "Level 2, Room 201" --out topic.bcf
 
 # List topics in a BCF file
-ifc-lite bcf list issues.bcf
+ifc-lite bcf list topics.bcf
 
 # Add a comment to a BCF file
-ifc-lite bcf add-comment --file issues.bcf --text "Fixed in revision 3" --out updated.bcf
+ifc-lite bcf add-comment --file topics.bcf --text "Fixed in revision 3" --out updated.bcf
 ```
 
 ---
diff --git a/docs/guide/quickstart.md b/docs/guide/quickstart.md
index a681034003..528cd890bc 100644
--- a/docs/guide/quickstart.md
+++ b/docs/guide/quickstart.md
@@ -3,7 +3,7 @@
 Get up and running with IFClite in under 5 minutes. Choose your path based on your use case.
 
 !!! tip "Beyond Single-Model Viewing"
-    IFClite also supports **multi-model federation** (loading and coordinating multiple IFC files), **BCF** (BIM Collaboration Format) for issue tracking, and **IDS** (Information Delivery Specification) for model validation. See the [Next Steps](#next-steps) section for links to these guides.
+    IFClite also supports **multi-model federation** (loading and coordinating multiple IFC files), **BCF** (BIM Collaboration Format) for topic tracking, and **IDS** (Information Delivery Specification) for model validation. See the [Next Steps](#next-steps) section for links to these guides.
 
 ## Choose Your Approach
 
@@ -582,7 +582,7 @@ try {
 - [Rendering Guide](rendering.md) - WebGPU rendering features
 - [Query Guide](querying.md) - Query entities and properties
 - [Federation Guide](federation.md) - Multi-model loading and coordination
-- [BCF Guide](bcf.md) - BIM Collaboration Format for issue tracking
+- [BCF Guide](bcf.md) - BIM Collaboration Format for topic tracking
 - [IDS Guide](ids.md) - Information Delivery Specification for validation
 - [2D Drawing Guide](drawing-2d.md) - Generate 2D drawings from models
 - [Mutations Guide](mutations.md) - Programmatic model modifications
diff --git a/docs/index.md b/docs/index.md
index 464116924a..cb46e66ce1 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -55,7 +55,7 @@
 - **Extract data** like properties, quantities, relationships, and spatial structure
 - **Validate models** against IDS (Information Delivery Specification) rules
 - **Generate 2D drawings** like floor plans, sections, and elevations from 3D models
-- **Collaborate** with BCF support for issues, viewpoints, and comments
+- **Collaborate** with BCF support for topics, viewpoints, and comments
 - **Export** to glTF, IFC, CSV, or Parquet
 - **Work with multiple models** at once with federated selection and visibility
 - **Automate from the terminal** with the [ifc-lite CLI](guide/cli.md), including an MCP server for AI assistants
diff --git a/packages/bcf-api/README.md b/packages/bcf-api/README.md
index 959dc6fe8c..ec304bf4da 100644
--- a/packages/bcf-api/README.md
+++ b/packages/bcf-api/README.md
@@ -1,6 +1,6 @@
 # @ifc-lite/bcf-api
 
-REST client for [buildingSMART BCF API](https://github.com/buildingSMART/BCF-API) (OpenCDE) servers. Connects to a BCF server, authenticates via OAuth2, and pulls projects, topics, comments and viewpoints into the [`@ifc-lite/bcf`](https://www.npmjs.com/package/@ifc-lite/bcf) in-memory model — so server-hosted issues flow through the same code paths as imported `.bcfzip` files.
+REST client for [buildingSMART BCF API](https://github.com/buildingSMART/BCF-API) (OpenCDE) servers. Connects to a BCF server, authenticates via OAuth2, and pulls projects, topics, comments and viewpoints into the [`@ifc-lite/bcf`](https://www.npmjs.com/package/@ifc-lite/bcf) in-memory model — so server-hosted topics flow through the same code paths as imported `.bcfzip` files.
 
 Works in the browser and in Node (uses the global `fetch`; injectable for tests). Implements the BCF API 2.1 routes.
 
diff --git a/packages/bcf/README.md b/packages/bcf/README.md
index 09652feba7..75c30a569e 100644
--- a/packages/bcf/README.md
+++ b/packages/bcf/README.md
@@ -1,6 +1,6 @@
 # @ifc-lite/bcf
 
-BCF (BIM Collaboration Format) support for IFClite. Reads and writes BCF 2.1 and 3.0 files — the issue-tracking format every BIM tool speaks (Revit, Archicad, Solibri, BIMcollab, etc.).
+BCF (BIM Collaboration Format) support for IFClite. Reads and writes BCF 2.1 and 3.0 files — the topic-tracking format every BIM tool speaks (Revit, Archicad, Solibri, BIMcollab, etc.).
 
 ## Installation
 
diff --git a/packages/bcf/src/index.ts b/packages/bcf/src/index.ts
index e3aa7018b3..cf9ddb1768 100644
--- a/packages/bcf/src/index.ts
+++ b/packages/bcf/src/index.ts
@@ -6,7 +6,7 @@
  * @ifc-lite/bcf - BIM Collaboration Format support
  *
  * This package provides BCF (BIM Collaboration Format) support for IFC-Lite.
- * It implements BCF 2.1 and 3.0 specifications for issue tracking in BIM projects.
+ * It implements BCF 2.1 and 3.0 specifications for topic tracking in BIM projects.
  *
  * @see https://github.com/buildingSMART/BCF-XML
  * @see https://www.buildingsmart.org/standards/bsi-standards/bim-collaboration-format/
@@ -121,7 +121,7 @@ export function createBCFProject(options?: {
 }
 
 /**
- * Create a new BCF topic (issue)
+ * Create a new BCF topic
  */
 export function createBCFTopic(options: {
   title: string;
diff --git a/packages/cli/src/commands/bcf.ts b/packages/cli/src/commands/bcf.ts
index e120096734..a722332c7a 100644
--- a/packages/cli/src/commands/bcf.ts
+++ b/packages/cli/src/commands/bcf.ts
@@ -24,7 +24,7 @@ export async function bcfCommand(args: string[]): Promise<void> {
       const description = getFlag(args, '--description');
       const author = getFlag(args, '--author') ?? 'cli@ifc-lite.com';
       const outPath = getFlag(args, '--out');
-      if (!title) fatal('Usage: ifc-lite bcf create --title "Issue" [--description "..."] [--author email] --out file.bcf');
+      if (!title) fatal('Usage: ifc-lite bcf create --title "Missing door" [--description "..."] [--author email] --out file.bcf');
       if (!outPath) fatal('--out is required for BCF creation');
 
       const project = await bcf.createProject({ name: 'CLI Project' });
diff --git a/packages/cli/src/index.ts b/packages/cli/src/index.ts
index 23a44e1d08..620f7556af 100644
--- a/packages/cli/src/index.ts
+++ b/packages/cli/src/index.ts
@@ -150,7 +150,7 @@ const HELP = `
     ifc-lite diagnose-geometry model.ifc --type IfcWall
     ifc-lite diagnose-geometry model.ifc --product 0YvCT2_$X3_xJG3rzD8L_8
     ifc-lite ids model.ifc requirements.ids --json
-    ifc-lite bcf create --title "Missing door" --out issue.bcf
+    ifc-lite bcf create --title "Missing door" --out topic.bcf
     ifc-lite clash model.ifc --matrix --json
     ifc-lite clash model.ifc --a "IfcDuct*|IfcPipe*" --b "IfcWall*" --mode clearance --clearance 0.05
     ifc-lite clash model.ifc --matrix --bcf clashes.bcfzip
diff --git a/packages/mcp/src/prompts/templates.ts b/packages/mcp/src/prompts/templates.ts
index b644a18e13..fcc8f97ef4 100644
--- a/packages/mcp/src/prompts/templates.ts
+++ b/packages/mcp/src/prompts/templates.ts
@@ -62,7 +62,7 @@ export const findFireRatedDoors: Prompt = {
           `2. For each non-compliant door, call \`bcf_topic_create\` titled "Fire rating below ${minimum} on <DoorName>" with the GlobalId in the description.`,
           `3. Attach a viewpoint with the door selected via \`bcf_viewpoint_create\`.`,
           `4. Report a summary of how many doors fail and the top 5 by name.`,
-          `5. Offer to export the BCF via \`bcf_export\` to ./fire-rating-issues.bcfzip.`,
+          `5. Offer to export the BCF via \`bcf_export\` to ./fire-rating-topics.bcfzip.`,
         ].join('\n')),
       ],
     };
diff --git a/packages/mcp/src/tools/bcf.ts b/packages/mcp/src/tools/bcf.ts
index aacb701911..880dd5137c 100644
--- a/packages/mcp/src/tools/bcf.ts
+++ b/packages/mcp/src/tools/bcf.ts
@@ -7,7 +7,7 @@
  *
  * Topics live inside a per-session BCF project that's lazy-created on first
  * write. We keep the project per ToolContext (server-wide, not per-model)
- * so an agent can collect issues across federated models, then export a
+ * so an agent can collect topics across federated models, then export a
  * single .bcfzip via `bcf_export`.
  */
 
diff --git a/packages/sandbox/src/bridge-clash.ts b/packages/sandbox/src/bridge-clash.ts
index 3e133b1153..d29c984f05 100644
--- a/packages/sandbox/src/bridge-clash.ts
+++ b/packages/sandbox/src/bridge-clash.ts
@@ -223,7 +223,7 @@ export function buildClashNamespace(): NamespaceSchema {
         returns: 'value',
         llmSemantics: {
           taskTags: ['inspect'],
-          useWhen: 'Cluster a clash result into BCF-ready groups before exporting issues.',
+          useWhen: 'Cluster a clash result into BCF-ready groups before exporting topics.',
         },
       },
       {
diff --git a/packages/sdk/src/namespaces/bcf.ts b/packages/sdk/src/namespaces/bcf.ts
index cca093ecf7..3a3776e851 100644
--- a/packages/sdk/src/namespaces/bcf.ts
+++ b/packages/sdk/src/namespaces/bcf.ts
@@ -7,7 +7,7 @@
  *
  * Full access to @ifc-lite/bcf for reading/writing BCF files,
  * managing collaboration data, creating viewpoints, and
- * converting between IDS reports and BCF issues.
+ * converting between IDS reports and BCF topics.
  */
 
 // ============================================================================
@@ -101,10 +101,10 @@ export class BCFNamespace {
   }
 
   // --------------------------------------------------------------------------
-  // Topic (issue) management
+  // Topic management
   // --------------------------------------------------------------------------
 
-  /** Create a new topic (issue). */
+  /** Create a new topic. */
   async createTopic(options: TopicOptions): Promise<unknown> {
     const mod = await loadBCF();
     return (mod.createBCFTopic as AnyFn)({
@@ -261,7 +261,7 @@ export class BCFNamespace {
   // IDS → BCF conversion
   // --------------------------------------------------------------------------
 
-  /** Convert an IDS validation report into BCF issues (one topic per failed spec). */
+  /** Convert an IDS validation report into BCF topics (one topic per failed spec). */
   async createFromIDSReport(report: unknown, options?: IDSBCFOptions): Promise<unknown> {
     const mod = await loadBCF();
     return (mod.createBCFFromIDSReport as AnyFn)(report, options);