diff --git a/src/generator/markdown.test.ts b/src/generator/markdown.test.ts
index 12fcf76..d9af481 100644
--- a/src/generator/markdown.test.ts
+++ b/src/generator/markdown.test.ts
@@ -148,6 +148,62 @@ describe('renderMarkdown', () => {
     expect(md).not.toContain('Hidden paragraph.');
     expect(md).not.toContain('A.');
   });
+  // Regression (#122): notes/continuations/vanish siblings must NOT consume a CSI
+  // number. A "Related Sections" pr1 whose first children are specifier-note banners
+  // rendered its 1..n list starting at the note count (e.g. "5." instead of "1.").
+  it('numbers pr2 siblings from 1, skipping leading note siblings', () => {
+    const tree: SpecTree = {
+      id: '00000000-0000-0000-0000-000000000001',
+      section: '09 05 00',
+      title: 'Numbering',
+      parts: [
+        {
+          id: '00000000-0000-0000-0000-000000000002',
+          type: 'part',
+          text: 'GENERAL',
+          meta: {},
+          children: [
+            {
+              id: '00000000-0000-0000-0000-000000000003',
+              type: 'article',
+              text: 'SUMMARY',
+              meta: {},
+              children: [
+                {
+                  id: '00000000-0000-0000-0000-000000000004',
+                  type: 'pr1',
+                  text: 'Related Sections:',
+                  meta: {},
+                  children: [
+                    {
+                      id: 'n1',
+                      type: 'note',
+                      text: 'banner one',
+                      children: [],
+                      meta: { vanish: true },
+                    },
+                    {
+                      id: 'n2',
+                      type: 'note',
+                      text: 'banner two',
+                      children: [],
+                      meta: { vanish: true },
+                    },
+                    { id: 'r1', type: 'pr2', text: 'Section 01 30 00', children: [], meta: {} },
+                    { id: 'r2', type: 'pr2', text: 'Section 01 33 00', children: [], meta: {} },
+                  ],
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    };
+    const md = renderMarkdown(tree);
+    expect(md).toContain('   1. Section 01 30 00');
+    expect(md).toContain('   2. Section 01 33 00');
+    expect(md).not.toContain('3. Section 01 30 00');
+  });
   it('renders empty tree without error', () => {
     const empty: SpecTree = {
       id: '00000000-0000-0000-0000-000000000001',
diff --git a/src/generator/markdown.ts b/src/generator/markdown.ts
index 4a5107a..588cfac 100644
--- a/src/generator/markdown.ts
+++ b/src/generator/markdown.ts
@@ -35,6 +35,29 @@ export function getLabel(type: NodeType, index: number, partNumber = 1): string
 
 const INDENT = '   ';
 
+// notes render as [NOTE] blockquotes, continuations as plain text, and vanish
+// nodes not at all — none carry a CSI number, so none may consume an ordinal.
+// Counting them shifted numbered siblings (#122): specifier-note banners pushed
+// a 1..15 "Related Sections" list to 5..20.
+function consumesNumber(node: SpecNode): boolean {
+  return node.type !== 'note' && node.type !== 'continuation' && !node.meta.vanish;
+}
+
+// Render a node's children, advancing the CSI ordinal only past numbered siblings
+// so notes/continuations/vanish nodes interleave without disturbing the sequence.
+function renderChildren(
+  children: readonly SpecNode[],
+  render: (child: SpecNode, ordinal: number) => string
+): string {
+  let ordinal = 0;
+  const out: string[] = [];
+  for (const child of children) {
+    out.push(render(child, ordinal));
+    if (consumesNumber(child)) ordinal += 1;
+  }
+  return out.join('');
+}
+
 function renderPrNode(node: SpecNode, index: number, depth: number): string {
   // note nodes always render as [NOTE] blockquotes regardless of meta.vanish — editorial
   // notes are structural metadata visible to spec writers, not owner-facing content.
@@ -49,26 +72,26 @@ function renderPrNode(node: SpecNode, index: number, depth: number): string {
   }
   const pad = INDENT.repeat(depth);
   const label = getLabel(node.type, index);
-  return [
-    `\n${pad}${label} ${node.text}`,
-    ...node.children.map((child, i) => renderPrNode(child, i, depth + 1)),
-  ].join('');
+  return (
+    `\n${pad}${label} ${node.text}` +
+    renderChildren(node.children, (child, ordinal) => renderPrNode(child, ordinal, depth + 1))
+  );
 }
 
 function renderArticle(node: SpecNode, index: number, partNumber: number): string {
   const label = getLabel('article', index, partNumber);
-  return [
-    `\n### ${label} ${node.text}\n`,
-    ...node.children.map((child, i) => renderPrNode(child, i, 0)),
-  ].join('');
+  return (
+    `\n### ${label} ${node.text}\n` +
+    renderChildren(node.children, (child, ordinal) => renderPrNode(child, ordinal, 0))
+  );
 }
 
 function renderPart(node: SpecNode, index: number): string {
   const label = getLabel('part', index);
-  return [
-    `\n## ${label} ${node.text}\n`,
-    ...node.children.map((child, i) => renderArticle(child, i, index + 1)),
-  ].join('');
+  return (
+    `\n## ${label} ${node.text}\n` +
+    renderChildren(node.children, (child, ordinal) => renderArticle(child, ordinal, index + 1))
+  );
 }
 
 export function renderMarkdown(tree: SpecTree): string {