diff --git a/pep-0643.rst b/pep-0643.rst
index c2307143d..31285e837 100644
--- a/pep-0643.rst
+++ b/pep-0643.rst
@@ -7,7 +7,7 @@ Status: Draft
 Type: Standards Track
 Content-Type: text/x-rst
 Created: 24-Oct-2020
-Post-History: 24-Oct-2020
+Post-History: 24-Oct-2020, 01-Nov-2020, 02-Nov-2020
 
 
 Abstract
@@ -86,6 +86,10 @@ This field will be multiple use, and will be allowed to contain the name
 of another core metadata field. The ``Dynamic`` metadata item is only
 allowed in source distribution metadata.
 
+If tools that read metadata encounter the ``Dynamic`` field anywhere except
+in a sdist, they MAY fail with an error. If they do not fail, they MUST
+ignore the field, and may report a warning.
+
 If a field is marked as ``Dynamic``, there is no restriction placed on
 its value in a wheel built from the sdist. A field which is marked as
 ``Dynamic``, MUST NOT have an explicit value in the sdist.