Answer prose round 1: the parsing codes list each reader, the CommonMark guarantee splits into three bullets, the migration row and two decisions read once

MIGRATION.md

@@ -8,7 +8,7 @@ Each call names the markdown it reads or writes:
 | --- | --- |
 | `adfToMarkdown` | `adfToLosslessMarkdown` |
 | `markdownToAdf`, for markdown `adfToMarkdown` wrote, edited since or not | `losslessMarkdownToAdf` |
-| `markdownToAdf`, for markdown no `adfToMarkdown` output went into | `portableMarkdownToAdf`, which keeps GFM's pipe tables and `~~` and reads alerts, callouts, task markers and `==` as nodes ([Portable markdown](README.md#portable-markdown)); or `commonMarkToAdf`, which reads all of them, a directive and an `adf:` fence as CommonMark does, as text and code |
+| `markdownToAdf`, for markdown no `adfToMarkdown` output went into | `portableMarkdownToAdf`, which reads GFM's pipe tables and `~~`, and reads alerts, callouts, task markers and `==` as nodes ([Portable markdown](README.md#portable-markdown)). Or `commonMarkToAdf`, which reads every one of those, and a directive and an `adf:` fence, as CommonMark does: as text and code |
 
 Directives moved under the `!adf:` prefix. `losslessMarkdownToAdf` reads `0.1.0`'s spelling without
 an error, turning each directive into text and each carried node into an `adf` code block. Before

README.md

@@ -10,10 +10,10 @@ products store as ADF.
 
 - **Lossless:** `adfToLosslessMarkdown` and `losslessMarkdownToAdf` give back the document they
   started from — panels, mentions, statuses and node types this version does not know included.
-- **Markdown in:** `portableMarkdownToAdf` reads a bot's or a model's markdown, `~~` and pipe tables
+- **Markdown in:** `portableMarkdownToAdf` reads a bot's or a model's markdown, including `~~` and
-  whose every row opens with a pipe included; `commonMarkToAdf` reads markdown known to be strict
+  pipe tables whose every row opens with a pipe. `commonMarkToAdf` reads strict CommonMark as its
-  CommonMark as its spec says, nothing in it becoming a table, task or panel. Both apart from raw
+  spec says: nothing becomes a table, task or panel. Both refuse raw HTML and the exceptions
-  HTML and the exceptions [The guarantees](#the-guarantees) lists.
+  [The guarantees](#the-guarantees) lists.
 - **Portable markdown, lossy:** `adfToPortableMarkdown` and `portableMarkdownToAdf` convert to and
   from the markdown that GitHub, GitLab and Obsidian render — GitHub Flavored Markdown's alerts,
   task lists and pipe tables, Obsidian Flavored Markdown's callouts and highlights.
@@ -184,11 +184,13 @@ UTF-16 code unit, a JavaScript string index rather than a codepoint or a byte of
 or before the refusal — currently the start of the line the enclosing block begins on; a later
 minor may narrow that, never widen it. For `not-a-string` it is `{ line: 1, offset: 0 }`.
 
-Parsing — `commonMarkToAdf` raises `not-a-string`, `unmappable-html` and `unmappable-image`;
+Parsing. Every reader also raises `unsupported-nesting-depth` from the "Either direction" table,
-`portableMarkdownToAdf` those and `malformed-pipe-table`; `losslessMarkdownToAdf` every row; and
+and:
-`htmlToAdf`, at `0.3.0`, the rows its dialect reaches. Every reader also raises
+
-`unsupported-nesting-depth`, and `losslessMarkdownToAdf` `unsupported-node-shape`, from the
+- `commonMarkToAdf`: `not-a-string`, `unmappable-html` and `unmappable-image`.
-"Either direction" table:
+- `portableMarkdownToAdf`: those and `malformed-pipe-table`.
+- `losslessMarkdownToAdf`: every row below, and `unsupported-node-shape`.
+- `htmlToAdf`, at `0.3.0`: the rows its dialect reaches.
 
 | Code | Fires when | What you can do |
 | --- | --- | --- |
@@ -228,15 +230,15 @@ Serves Goals 1, 4 and 5.
 - Markdown this library reads, and markdown it writes, means what the CommonMark spec says; from
   `0.3.0`, well-formed HTML means what the HTML standard says, read or written. The bullets below
   name every exception.
-- CommonMark is valid input to every reader apart from the raw HTML `unmappable-html` names, with
+- CommonMark is valid input to every reader, apart from the raw HTML `unmappable-html` names and
-  one gap: a CommonMark image fits only as its own title-less paragraph; mid-text and titled images
+  one gap: a CommonMark image fits only as its own title-less paragraph. Mid-text and titled images
   are error results, save an image inside another's description, which flattens into the alt text.
-  `commonMarkToAdf` reads it as its spec says. `losslessMarkdownToAdf` has four carve-outs —
+- `commonMarkToAdf` claims nothing else. `losslessMarkdownToAdf` claims four shapes: literal text
-  literal text matching directive, pipe-table or strikethrough syntax, and a code fence whose info
+  matching directive, pipe-table or strikethrough syntax, and a code fence whose info string opens
-  string opens `adf:`, are claimed (each can be kept literal — `spec/flavour.md`) — and
+  `adf:`. Each can be kept literal (`spec/flavour.md`). `portableMarkdownToAdf` claims what
-  `portableMarkdownToAdf` claims what [Portable markdown](#portable-markdown) lists. Converting a
+  [Portable markdown](#portable-markdown) lists.
-  read document back with `adfToLosslessMarkdown` yields the library's canonical spelling, which
+- A document any reader built, written back with `adfToLosslessMarkdown`, takes the library's
-  round-trips byte-identically.
+  canonical spelling, which round-trips byte-identically.
 - Four CommonMark spellings parse without an error and build a document the reference
   implementation renders differently: `[](/url)` and `[]()` stay literal text against CommonMark's
   empty link, a list continuing past a marker change stays one list against CommonMark's two, a
@@ -249,7 +251,7 @@ Serves Goals 1, 4 and 5.
   levels, and the node shapes the `unsupported-node-shape` row lists. Show the refusal and keep the
   document read-only; saving markdown you could not produce is the loss the round-trip exists to
   stop.
-- The pipe table `losslessMarkdownToAdf` and `portableMarkdownToAdf` read narrows GFM's twice: every
+- The pipe table that `losslessMarkdownToAdf` and `portableMarkdownToAdf` read narrows GFM's twice: every
   row opens with a pipe, so GFM's bare form is an error result rather than the prose it reads as,
   and an alignment colon in the delimiter row is an error too — ADF holds no column alignment. The
   trailing pipe is canonical output, optional in input.

docs/decisions.md

@@ -181,7 +181,8 @@ opener nests by itself and leaf versus container falls out of the node's content
 CommonMark is a subset of the lossless flavour, with carve-outs (`spec/flavour.md`): literal text
 shaped like a directive, a pipe table or a `~~` pair is claimed, and so is a code fence whose info
 string opens `adf:` (§The carry fence names the node type) — plus one image gap, which `todo.md`
-item 65 ends. `commonMarkToAdf` claims none of them (§Each call names its flavour).
+item 65 ends. `commonMarkToAdf` claims none of the carve-outs; the image gap holds there too (§Each call names
+its flavour).
 
 ## Tables
 
@@ -556,8 +557,8 @@ suite's answers are HTML ADF cannot be compared against.
 
 Each example is a named error or markdown `commonMarkToAdf` reads to a document that
 `adfToLosslessMarkdown` writes and `losslessMarkdownToAdf` reads back deep-equal, since CommonMark
-has no writer of its own; its reference HTML's text, tags stripped and entities decoded, equals the
+has no writer of its own. The example's reference HTML's text, tags stripped and entities decoded,
-parsed document's; and its elements count the marks and nodes they map to. The fixpoint alone
+equals the parsed document's; and its elements count the marks and nodes they map to. The fixpoint alone
 passes a parser returning the empty document, the text alone one dropping every emphasis. An
 exception is the maintainer's to add, and valid CommonMark parsing to a document
 `adfToLosslessMarkdown` refuses is a bug to fix, never an exception.

src/markdown/portable/conventions.ts

@@ -15,7 +15,6 @@ export type Claims = {
   taskMarkers: boolean
 }
 
-// The writer spells pipe tables and `~~` in every flavour it writes.
 type WrittenClaims = Claims & { pipeTables: true; strikethrough: true }
 
 // Directives exclude alerts and highlights: an expand directive leaves `inExpand` unset and a directive's slot reads `==`.

todo.md

@@ -189,7 +189,7 @@ candidates are `@atlaskit/editor-markdown-transformer`, `adf-to-markdown`, `adf-
 Models write `|:---|` delimiter rows and tables without a leading pipe; both are
 `malformed-pipe-table` today, and `portableMarkdownToAdf` is the bot's reader. ADF holds no column
 alignment, so the portable reader drops it (Goal 7: form, never content). The lossless reader keeps
-§Tables' narrowing. Found by the product-owner review of item 43, 2026-10-09.
+§Tables' narrowing.
 
 ### 80. Name the node's path and the attribute key when `not-an-adf-document` refuses a node inside the document.