diff --git a/Documentation/docs/migration_guides/itk_6_migration_guide.md b/Documentation/docs/migration_guides/itk_6_migration_guide.md
index 3a62bd79989..75663509ae5 100644
--- a/Documentation/docs/migration_guides/itk_6_migration_guide.md
+++ b/Documentation/docs/migration_guides/itk_6_migration_guide.md
@@ -8,3 +8,10 @@ from v4 to v5 can be found [here](./itk_5_migration_guide.md).
 Require modern C++ language feature use
 ---------------------------------------
 Many backward compatible/ forward enabling compiler features are now required to be used.
+
+Replace `ITKv5_CONST` with `const`
+
+Remove support for ITKv4 interfaces
+-----------------------------------
+
+`ITKV4_COMPATIBILITY` is no longer a supported option.