diff --git a/docs/ADR-0003-html-markdown-representation.md b/docs/ADR-0003-html-markdown-representation.md
index f06214b..746d7ea 100644
--- a/docs/ADR-0003-html-markdown-representation.md
+++ b/docs/ADR-0003-html-markdown-representation.md
@@ -30,7 +30,8 @@ Reflowable formats have no fixed pages:
 - `offsetMap` is a **single synthetic range** on page 1 covering
   `[0, canonicalText.length)` with no gaps. This keeps
   `TextPositionSelector` usable without inventing physical page geometry.
-- `structureMap` remains `never` in the engine contract and is not populated.
+- `structureMap` is omitted by ingest; viewer adapters in `evidence-anchor`
+  may populate it at selection time (see `SharedContracts.md` §3).
 
 ### Canonical text