diff --git a/docs/decisions.md b/docs/decisions.md
index f93d396..38bea5b 100644
--- a/docs/decisions.md
+++ b/docs/decisions.md
@@ -113,7 +113,9 @@ node's JSON without `type`: ```` ```adf:blockCard ````. A type no info string ca
 rule a code language follows — leaves the info string `adf:` and keeps `type` in the body. Every
 info string opening `adf:` is reserved, so a `codeBlock` whose language opens so takes the
 `language` attribute, and `carry` is an ordinary language. A body holding `type` under a named
-type, or an `adf:` fence whose type an info string carries, is `unsupported-node-shape`.
+type, or an `adf:` fence whose type an info string carries, is `unsupported-node-shape`. The
+reservation claims a fence CommonMark reads as code until `todo.md` item 43 gives CommonMark its own
+reader.
 
 ## A code block is a fence per text node
 
@@ -171,7 +173,9 @@ opener nests by itself and leaf versus container falls out of the node's content
 2026-08-23, the maintainer. Goal 4. Valid while prose rarely writes the shapes the carve-outs claim.
 
 Plain CommonMark is a subset, with carve-outs (`spec/flavour.md`): literal text shaped like a
-directive, a pipe table or a `~~` pair is claimed — plus one image gap.
+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. `todo.md` item 43 ends the
+claims, giving CommonMark its own reader.
 
 ## Tables
 
diff --git a/todo.md b/todo.md
index 75e3bf0..fba68d1 100644
--- a/todo.md
+++ b/todo.md
@@ -68,7 +68,8 @@ HTML in input). The set sorts per `docs/decisions.md` §Foreign HTML sorts three
 ### 43. Give each markdown input its own reader, strict to its own standard.
 
 Today `markdownToAdf` reads CommonMark and the lossless flavour as one input: text shaped like a
-directive, a pipe table or a `~~` pair becomes a flavour node where CommonMark reads plain text. A
+directive, a pipe table or a `~~` pair becomes a flavour node where CommonMark reads plain text, and
+a code fence whose info string opens `adf:` becomes the block carry where CommonMark reads code. A
 caller names the markdown it hands in: CommonMark, read as its spec says, or the lossless flavour,
 read as `spec/flavour.md` says. Breaking: `MIGRATION.md` says which call a caller takes.