diff --git a/mkdocs.yml b/mkdocs.yml
index 62f8047bfb..1dc1c63a4d 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -24,7 +24,7 @@ strict: true
 validation:
   nav:
     omitted_files: info  # allow during development where there are moving parts
-    not_found: info      # allow during development where there are moving parts
+    not_found: warn      # warn if a file is referenced in the nav but not included in the build
     absolute_links: warn
   links:
     not_found: warn
@@ -41,7 +41,7 @@ nav:
 - '5. Model and serializations': serializations.md
 - model:  # [MODEL_PLACEHOLDER], to be replaced by content from mkdocs-files.yml
 - annexes:
-  - 'A. Changes from the previous standard': annexes/diffs-from-previous-iso.md
+  - 'A. Changes from the previous standard': annexes/changes-from-previous-iso.md
   - 'B. RDF model definition and diagrams': annexes/rdf-model.md
   - 'C. SPDX license expressions': annexes/spdx-license-expressions.md
   - 'D. SPDX license list matching guidelines': annexes/license-matching-guidelines-and-templates.md
@@ -54,4 +54,3 @@ nav:
 draft_docs: |  # for preview with `mkdocs serve`, but excluded from `mkdocs build`
   omg-preface.md
   iso-foreword.md
-  conformance.md