Merge branch '6.4' into 7.2

* 6.4:
  Minor reword
  Add note to IBAN validator documentation about whitespace handling

Author: javiereguiluz

reference/constraints/Iban.rst

@@ -85,6 +85,15 @@ will contain an International Bank Account Number.
 
 .. include:: /reference/constraints/_empty-values-are-valid.rst.inc
 
+.. note::
+
+    For convenience, the IBAN validator accepts values with various types of
+    whitespace (e.g., regular, non-breaking, and narrow non-breaking spaces),
+    which are automatically removed before validation. However, this flexibility
+    can cause issues when storing IBANs or sending them to APIs that expect a
+    strict format. To ensure compatibility, normalize IBANs by removing
+    whitespace and converting them to uppercase before storing or processing.
+
 Options
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