Keep the reserved info string beside the fence it spells, and one fenced-block spelling for both

AGENTS.md

@@ -27,7 +27,9 @@ Round-trip equality is a property tested over a corpus, not a claim made in pros
 ## 3. Unknown input policy
 
 - Unknown ADF node: carried opaquely — raw JSON rides a dedicated syntax in both formats and
-  restores to a deep-equal node. The round-trip holds for documents newer than the library.
+  restores to a deep-equal node. The round-trip holds for documents newer than the library. It is
+  the node *type* that is unknown: a known type standing where its content model forbids stays an
+  error result, never a carry.
 - Unmappable foreign HTML element: error result naming the element — never a silent drop.
 - Bare `@name` / `:smile:` in typed text: stays a text node. Only directives produce
   mention/emoji/media nodes; resolving names to ids needs I/O, which is the consumer's job.
@@ -116,8 +118,8 @@ live Atlassian APIs; property-generated ADF trees; the CommonMark spec suite aga
 - A readable spelling tried ahead of a general one — the image, the pipe table, a pipe cell —
   returns `string | undefined`, never a `Result`: any failure is the fallback signal, and the
   general form owns the refusal. Refusing there refuses a document the general form spells.
-- Nothing recurses unbounded: the guards walk iteratively, and blocks, marks and attribute values
-  are all held to 500 levels, so a deep document is a `Result` rather than the stack overflow that
+- Nothing recurses unbounded: the guards walk iteratively, and blocks, marks, attribute values and
+  a carried node's JSON are all held to 500 levels, so a deep document is a `Result` rather than the stack overflow that
   waits near 2000.
 - No casts: `as`, `as unknown as`, non-null `!`. A boundary owes a type guard validating the
   fields it claims (`isAdfDocument`); past it everything is typed. Make invalid states