diff --git a/AGENTS.md b/AGENTS.md
index 1257ae1..0a4b23a 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -158,20 +158,14 @@ converts no raw HTML, so at `0.2.0` the mapped elements stop erroring and the co
 no ADF node carries. A refusal found before its path is known — the block walk's, a directive
 reader's — is a `ConvertFault`, the code and message alone; the node walk attaches the path as it
 descends, so a document reports its first error in document order. `not-an-adf-document` carries
-the document's own path throughout: eight of the guard's nine branches read the document's own
-shape, and threading a path to the ninth — a malformed node anywhere in the tree — wants the
+the document's own path throughout: seven of the guard's eight branches read the document's own
+shape, and threading a path to the eighth — a malformed node anywhere in the tree — wants the
 manual stack §11's no-recursion rule forces, whose empty half no input reaches. The message names
-the violation instead. Depth is not one of the nine: `adfDocumentFault` returns the code with the
-message, so an attribute value past 500 levels is `unsupported-nesting-depth` from the emitter as
-it already is from the parser, both directions refusing the same value. A node's attribute is
-counted from the value itself, never from the `attrs` object holding it; a mark's is counted three
-levels in, because the block directive spells the whole mark set as one JSON attribute and the
-parser reads the value at the bottom of array, mark and `attrs`. `isAdfDocument` is true for a depth fault:
-a deep document is a document, as the 2000-level blocks and the 600-deep marks the guard already
-waves through are, and depth is the walks' answer rather than the shape's. A non-finite number
-stays parted where depth is joined: the parse says `unsupported-node-shape` because the markdown is
-at fault, the emit `not-an-adf-document` because the input is, and unlike depth nothing round-trips
-inconsistently between them.
+the violation instead. An attribute value past 500 levels is `unsupported-nesting-depth` in both
+directions, the guard included. An attribute is counted from its value; a spelling that nests it
+deeper — the block directive's `marks`, the carry — refuses in its own format, as its parser does.
+A non-finite number takes two codes: `unsupported-node-shape` parsing, `not-an-adf-document`
+emitting — no document holds one, so no round-trip crosses them.
 
 `position` is the parse side's alone: an emitter reads no source, so an emit error carries `path`
 and nothing more. It is `{ line, offset }` at the start of the line the block holding the refusal
diff --git a/src/adf/document.test.ts b/src/adf/document.test.ts
index 4efd5f9..20e3b37 100644
--- a/src/adf/document.test.ts
+++ b/src/adf/document.test.ts
@@ -61,16 +61,15 @@ test('rejects a node whose shape ProseMirror JSON cannot hold', () => {
 })
 
 test('names the attribute nesting past the levels the parser reads one at, and still calls the value a document', () => {
-  const deeper = (key: string, type: string, levels: number = largestNesting): string =>
-    `the ${key} attribute of ${type} nests deeper than the ${levels} levels an attribute carries`
+  const deeper = (key: string, type: string): string => `the ${key} attribute of ${type} nests deeper than the ${largestNesting} levels an attribute carries`
   assert.equal(fault(withAttribute(nested(largestNesting))), 'accepted')
   assert.equal(fault(withAttribute(nested(largestNesting + 1))), deeper('a', 'paragraph'))
   assert.equal(faultCode(withAttribute(nested(largestNesting + 1))), 'unsupported-nesting-depth')
   assert.equal(isAdfDocument(withAttribute(nested(largestNesting + 1))), true)
   const marked = (levels: number): unknown => ({ content: [{ marks: [{ attrs: { a: nested(levels) }, type: 'link' }], text: 'x', type: 'text' }], type: 'doc', version: 1 })
-  assert.equal(fault(marked(largestNesting - 3)), 'accepted')
-  assert.equal(fault(marked(largestNesting - 2)), deeper('a', 'link', largestNesting - 3))
-  assert.equal(isAdfDocument(marked(largestNesting - 2)), true)
+  assert.equal(fault(marked(largestNesting)), 'accepted')
+  assert.equal(fault(marked(largestNesting + 1)), deeper('a', 'link'))
+  assert.equal(isAdfDocument(marked(largestNesting + 1)), true)
 })
 
 test('accepts the JSON values an attribute may hold', () => {
diff --git a/src/adf/document.ts b/src/adf/document.ts
index 765ab9b..490c5ac 100644
--- a/src/adf/document.ts
+++ b/src/adf/document.ts
@@ -23,9 +23,6 @@ export type AdfDocument = {
   version: number
 }
 
-// A block directive spells the whole mark set as one JSON attribute, so a mark's value sits three levels inside it.
-const markAttributeNesting = largestNesting - 3
-
 const documentKeys = ['content', 'type', 'version']
 const markKeys = ['attrs', 'type']
 const nodeKeys = ['attrs', 'content', 'marks', 'text', 'type']
@@ -47,8 +44,8 @@ export function adfDocumentFault(value: unknown): ConvertFault | undefined {
   return nestingFault(content)
 }
 
-export function attributeNestingMessage(key: string, type: string, levels: number = largestNesting): string {
-  return `the ${key} attribute of ${type} nests deeper than the ${levels} levels an attribute carries`
+export function attributeNestingMessage(key: string, type: string): string {
+  return `the ${key} attribute of ${type} nests deeper than the ${largestNesting} levels an attribute carries`
 }
 
 export function carriesOnly(node: AdfNode, attributes: readonly string[]): boolean {
@@ -116,15 +113,15 @@ function nestingFault(nodes: readonly AdfNode[]): ConvertFault | undefined {
 
 function marksFault(marks: readonly AdfMark[]): ConvertFault | undefined {
   for (const mark of marks) {
-    const fault = attributesFault(nodeAttrs(mark), mark.type, markAttributeNesting)
+    const fault = attributesFault(nodeAttrs(mark), mark.type)
     if (fault !== undefined) return fault
   }
   return undefined
 }
 
-function attributesFault(attrs: AdfAttributes, type: string, levels: number = largestNesting): ConvertFault | undefined {
+function attributesFault(attrs: AdfAttributes, type: string): ConvertFault | undefined {
   for (const [key, value] of Object.entries(attrs)) {
-    if (overNested(value, levels)) return { code: 'unsupported-nesting-depth', message: attributeNestingMessage(key, type, levels) }
+    if (overNested(value)) return { code: 'unsupported-nesting-depth', message: attributeNestingMessage(key, type) }
   }
   return undefined
 }
diff --git a/src/markdown/emit/adf-to-markdown.test.ts b/src/markdown/emit/adf-to-markdown.test.ts
index e5a2969..daf574f 100644
--- a/src/markdown/emit/adf-to-markdown.test.ts
+++ b/src/markdown/emit/adf-to-markdown.test.ts
@@ -353,8 +353,8 @@ test('refuses marks and attributes nested deeper than the emitter carries', () =
   assert.equal(code(adfToMarkdown(document(paragraph({ marks, text: 'x', type: 'text' })))), 'unsupported-nesting-depth')
   let attrs: AdfMark['attrs'] = { depth: 'x' }
   for (let depth = 0; depth < 600; depth += 1) attrs = { depth: attrs }
-  const deeper = (key: string, type: string, levels: number = largestNesting): string =>
-    `unsupported-nesting-depth: the ${key} attribute of ${type} nests deeper than the ${levels} levels an attribute carries`
+  const deeper = (key: string, type: string): string =>
+    `unsupported-nesting-depth: the ${key} attribute of ${type} nests deeper than the ${largestNesting} levels an attribute carries`
   const nested = (levels: number): JsonValue => {
     let value: JsonValue = 1
     for (let level = 0; level < levels; level += 1) value = [value]
@@ -375,11 +375,18 @@ test('refuses marks and attributes nested deeper than the emitter carries', () =
     assert.deepEqual(toEditorNormal(read.value), document(node))
   }
 
-  assert.equal(markdown(adfToMarkdown(document(paragraph({ marks: [{ attrs, type: 'em' }], text: 'x', type: 'text' })))), deeper('depth', 'em', largestNesting - 3))
+  assert.equal(markdown(adfToMarkdown(document(paragraph({ marks: [{ attrs, type: 'em' }], text: 'x', type: 'text' })))), deeper('depth', 'em'))
+  assert.equal(
+    markdown(adfToMarkdown(document(paragraph({ marks: [{ attrs: { deep: nested(largestNesting) }, type: 'em' }], text: 'x', type: 'text' })))),
+    `unsupported-nesting-depth: a carried node's JSON nests deeper than the ${largestNesting} levels its position leaves`,
+  )
   assert.equal(markdown(adfToMarkdown(document(paragraph(card(largestNesting + 1))))), deeper('data', 'inlineCard'))
   assert.deepEqual(path(adfToMarkdown(document(paragraph(card(largestNesting + 1))))), [])
   roundTrips(paragraph(card(largestNesting)))
-  assert.equal(markdown(adfToMarkdown(document(marked(largestNesting - 2)))), deeper('deep', 'em', largestNesting - 3))
+  assert.equal(markdown(adfToMarkdown(document(marked(largestNesting - 2)))), deeper('marks', 'panel'))
+  assert.deepEqual(path(adfToMarkdown(document(marked(largestNesting - 2)))), ['content', 0])
+  const markedCode: AdfNode = { content: [{ text: 'x', type: 'text' }], marks: [{ attrs: { deep: nested(largestNesting - 2) }, type: 'em' }], type: 'codeBlock' }
+  assert.equal(markdown(adfToMarkdown(document(markedCode))), deeper('marks', 'codeBlock'))
   roundTrips(marked(largestNesting - 3))
 })
 
diff --git a/src/markdown/emit/adf-to-markdown.ts b/src/markdown/emit/adf-to-markdown.ts
index f0c176a..10d2825 100644
--- a/src/markdown/emit/adf-to-markdown.ts
+++ b/src/markdown/emit/adf-to-markdown.ts
@@ -147,9 +147,10 @@ function emitDirectiveBlock(node: AdfNode, model: BlockNodeModel, path: ConvertE
   if (node.text !== undefined) return failure('unsupported-node-shape', `a ${node.type} carries no text: this one holds text`, path)
   if (blockDirectiveForm(node.type) === 'leaf' && nodeContent(node).length > 0) return failure('unsupported-node-shape', `a ${node.type} holds no content: this one holds some`, path)
   if (model.contentModel === 'code') return emitCodeDirective(node, model, path, depth)
-  const opener = spellBlockDirectiveOpener(node, model)
+  const opener = spellBlockDirectiveOpener(node, model, path)
   if (opener === undefined) return commonMarkLine(carriedBlock(node, path, depth))
-  return emitDirectiveBody(node, model, opener, path, walkBody)
+  if (!opener.ok) return opener
+  return emitDirectiveBody(node, model, opener.value, path, walkBody)
 }
 
 function emitDirectiveBody(node: AdfNode, model: BlockNodeModel, opener: string, path: ConvertErrorPath, walkBody: () => Result<Walk>): Result<EmittedBlock> {
@@ -186,11 +187,12 @@ function tryCodeBlock(node: AdfNode, path: ConvertErrorPath): Result<EmittedBloc
 
 function emitCodeDirective(node: AdfNode, model: BlockNodeModel, path: ConvertErrorPath, depth: number): Result<EmittedBlock> {
   const slot = languageSlot(nodeAttrs(node)['language'])
-  const opener = spellBlockDirectiveOpener(node, model, slot.kind === 'attribute' ? [] : ['language'])
+  const opener = spellBlockDirectiveOpener(node, model, path, slot.kind === 'attribute' ? [] : ['language'])
   if (opener === undefined) return commonMarkLine(carriedBlock(node, path, depth))
+  if (!opener.ok) return opener
   const text = codeBlockText(node, path)
   if (!text.ok) return text
-  return success(directivePair(node, opener, fencedCodeBlock(slot.kind === 'fence' ? slot.info : '', text.value)))
+  return success(directivePair(node, opener.value, fencedCodeBlock(slot.kind === 'fence' ? slot.info : '', text.value)))
 }
 
 function codeBlockText(node: AdfNode, path: ConvertErrorPath): Result<string> {
diff --git a/src/markdown/emit/block-directive-spelling.ts b/src/markdown/emit/block-directive-spelling.ts
index 5598932..1460699 100644
--- a/src/markdown/emit/block-directive-spelling.ts
+++ b/src/markdown/emit/block-directive-spelling.ts
@@ -1,12 +1,14 @@
 import type { AdfNode } from '../../adf/document.ts'
 import type { BlockNodeModel } from '../../adf/block-nodes.ts'
+import { attributeNestingMessage, nodeAttrs, nodeMarks } from '../../adf/document.ts'
 import { blockArgument } from '../block-directive-arguments.ts'
+import { failure, success, type ConvertErrorPath, type Result } from '../../result.ts'
 import { isBareToken, spellAttributes, spellDirectiveOpener, spellJsonAttribute, spellVocabulary } from '../directive-syntax.ts'
 import { markValues, marksAttribute } from '../block-directive-marks.ts'
-import { nodeAttrs, nodeMarks } from '../../adf/document.ts'
+import { overNested } from '../../json-value.ts'
 import { vocabularyPairs } from '../../adf/attribute-vocabulary.ts'
 
-export function spellBlockDirectiveOpener(node: AdfNode, model: BlockNodeModel, spelledByBody: readonly string[] = []): string | undefined {
+export function spellBlockDirectiveOpener(node: AdfNode, model: BlockNodeModel, path: ConvertErrorPath, spelledByBody: readonly string[] = []): Result<string> | undefined {
   const argumentAttribute = blockArgument(node.type)
   const slot = bareArgument(node, argumentAttribute)
   if (slot === undefined) return undefined
@@ -15,8 +17,12 @@ export function spellBlockDirectiveOpener(node: AdfNode, model: BlockNodeModel,
   if (pairs === undefined) return undefined
   const spelledPairs = spellVocabulary(pairs)
   const marks = nodeMarks(node)
-  if (marks.length > 0) spelledPairs.push([marksAttribute, spellJsonAttribute(markValues(marks))])
-  return spellDirectiveOpener(node.type, slot.argument, spellAttributes(spelledPairs))
+  if (marks.length > 0) {
+    const values = markValues(marks)
+    if (overNested(values)) return failure('unsupported-nesting-depth', attributeNestingMessage(marksAttribute, node.type), path)
+    spelledPairs.push([marksAttribute, spellJsonAttribute(values)])
+  }
+  return success(spellDirectiveOpener(node.type, slot.argument, spellAttributes(spelledPairs)))
 }
 
 // `undefined` where the argument slot holds a value no bare token spells.
diff --git a/todo-history.md b/todo-history.md
index f87d4e7..30db6d5 100644
--- a/todo-history.md
+++ b/todo-history.md
@@ -1018,6 +1018,18 @@ The done `todo.md` items in full, as they were written. `todo.md` keeps a one-li
       `parse/` imports `emit/` twice — `commonMarkSpelling` and `openingLinkTakesDirective` — and
       §11 says those two are the whole of the seam a `../emit/` grep under `parse/` reads.
 
+- [x] **32 — The mark depth `adf/` counts is stated in ADF's terms (`0.2.0`).**
+      `document.ts`'s `markAttributeNesting` is `largestNesting - 3`, and both the comment above it
+      and AGENTS.md §8 give the reason as markdown's: the block directive spells the whole mark set
+      as one JSON attribute, so the parser reads the value at the bottom of array, mark and
+      `attrs`. That is a format's spelling deciding a constant inside the directory §11 forbids to
+      know a format. Move the derivation to where that spelling lives, or state the three levels in
+      ADF's own vocabulary. Before 7 gives the constant a second format whose spelling may not
+      spend the same three levels.
+      **Done** (2026-09-23): `adf/` counts a mark's attribute from its value at 500, as a node's;
+      the block directive's `marks` spelling refuses its own over-deep JSON with the parser's
+      message and the node's path, and §8 says a deeper spelling refuses in its own format.
+
 ## 5 — Ship `0.1.0`
 
 - [ ] **5 — Ship `0.1.0`.** Only the maintainer's own acts are left (§15): make the Gitea repo
diff --git a/todo.md b/todo.md
index 0f9ac99..a2dc67f 100644
--- a/todo.md
+++ b/todo.md
@@ -56,14 +56,6 @@ chunk clearing a §11 seam.
       upward, so the first raise to the measured figure reddens a run that changed nothing. Make
       the measurement repeatable, or state the number the floor may be raised to and why it is not
       the measured one.
-- [ ] **32 — The mark depth `adf/` counts is stated in ADF's terms (`0.2.0`).**
-      `document.ts`'s `markAttributeNesting` is `largestNesting - 3`, and both the comment above it
-      and AGENTS.md §8 give the reason as markdown's: the block directive spells the whole mark set
-      as one JSON attribute, so the parser reads the value at the bottom of array, mark and
-      `attrs`. That is a format's spelling deciding a constant inside the directory §11 forbids to
-      know a format. Move the derivation to where that spelling lives, or state the three levels in
-      ADF's own vocabulary. Before 7 gives the constant a second format whose spelling may not
-      spend the same three levels.
 - [ ] **23 — The block-directive fragments are one file (`0.2.0`).** `block-directive-arguments.ts`,
       `-forms.ts` and `-marks.ts` are three files under 25 lines answering one question. Fold them,
       and take `src/markdown/` — the worst level both architects named, 13 entries with no
@@ -292,6 +284,7 @@ chunk clearing a §11 seam.
 - [x] **28 — `emitLine`'s retry loop cannot spin (`0.2.0`).**
 - [x] **29 — The README reads raw HTML as refused for good (`0.2.0`).**
 - [x] **30 — AGENTS.md says each thing once (`0.2.0`).**
+- [x] **32 — The mark depth `adf/` counts is stated in ADF's terms (`0.2.0`).**
 
 ## The ADF inventory to cover