Keep an image's description whole, and the brackets of an empty link text literal

todo.md

@@ -260,6 +260,14 @@ detail is settled at its own milestone.
         no ADF node carries. And the CommonMark image shape lands here rather than at 3h: once
         `[…](…)` reads, a lone `![alt](url)` would otherwise misparse as text plus a link, so 3h
         keeps the rest of the media family and loses only that line.
+        **Settled** (the maintainer, 2026-08-31, on the review): an empty link text — `[](/u)` —
+        leaves the brackets the text they are rather than minting a refusal or dropping the
+        destination, giving the label back the way an unresolved pair does, so the shortcut behind
+        `[][r]` still reads. A description holding an image flattens to that image's own alt, which
+        is what alt text means and what keeps the documented gap to mid-text and titled images; a
+        break of either kind inside one reads as a space. And a destination or title whose entity
+        reference decodes to a control character — `[a](/x
y)` — joins 3k's exception list
+        beside the two above: the reader takes cmark's reading, the emitter has no spelling for it.
   - [ ] **3f — The directive grammar.** The three forms — inline `:name[content]{attrs}`,
         container `:::name arg {attrs}`, leaf `::name arg {attrs}` — the attribute grammar with
         its quoting and escapes, the fence-length and nesting rules, and the malformed list