diff --git a/AiBook_PRD.md b/AiBook_PRD.md
index 9dcad9a..7cf2e5f 100644
--- a/AiBook_PRD.md
+++ b/AiBook_PRD.md
@@ -204,7 +204,7 @@ still the unit of *practice* (and of activation). The chapter is the unit of *re
 11. Author, sources, last updated
 
 **Addressability**
-- Every workflow has a stable ID (e.g. `RE-04`) and a URL that opens the chapter scrolled to
+- Every workflow has a stable ID (e.g. `RE-01`) and a URL that opens the chapter scrolled to
   that block (and a focused/print view of the same block). Campaign samples, clone-and-run
   kits, and Workflow-of-the-Week link here — never to an essay with no way in.
 - PDF matches this stack: chapter essay + in-place recipes. Print and web must not drift.