Limit the identical-refusal claim to writers, say non-empty content, and warn of stored carries

docs/decisions.md

@@ -758,12 +758,13 @@ while Atlassian's schema forbids shapes a converter would otherwise meet.
 A shape Atlassian's schema forbids, and the library refuses, is refused in the first step, where
 the document is checked once: `writableContent` opens every writer, and `carriedNode` opens every
 carry reader's node. No converter refuses one. A document one call refuses on a schema rule every
-call refuses alike, with one code, message and path, wherever the shape stands, in a carried node
-too. The first step refuses an `inlineCard` with a `link` mark as `unsupported-node-shape`: the
+writer refuses alike, with one code, message and path, wherever the shape stands, in a carried node
+too, and a carry reader refuses it with the same code and the writers' message after its holder's
+name. The first step refuses an `inlineCard` with a `link` mark as `unsupported-node-shape`: the
 schema gives a card the `annotation` mark alone (§The node tables answer to Atlassian's schema),
 and HTML nests no `<a>` in an `<a>`. `adfToLosslessMarkdown` still refuses two more, on a node not
 riding the carry: a block or non-text inline node holding `text`, and a leaf block or non-text
-inline node holding `content`. `todo.md` item 167 moves them, and until it ships this entry does
+inline node holding a non-empty `content`. `todo.md` item 167 moves them, and until it ships this entry does
 not hold for them.
 
 Nothing else joins the first step. Nothing refuses a node type, mark or attribute the schema does

todo.md

@@ -118,7 +118,9 @@ are". It replaces item 68, which would have carried these shapes. Move into `ref
 
 Atlassian's schema gives each such node no `text` or `content` (`additionalProperties` is false).
 Breaking: `adfToHtml` and `adfToPortableMarkdown` refuse these shapes too, and so does
-`adfToLosslessMarkdown` inside a node that rides the carry, where it writes them today. Say so in
+`adfToLosslessMarkdown` inside a node that rides the carry, where it writes them today. Both carry
+readers refuse them too, so a stored markdown or HTML document whose carry holds one stops
+reading; `MIGRATION.md` says to convert it once with the last version that reads it. Say so in
 `CHANGELOG.md` and `MIGRATION.md`. Search the writers for any other refusal of a shape the schema
 forbids, and `carriedNode` for one the readers still build.