diff --git a/org.fortiss.tooling.base/trunk/src/org/fortiss/tooling/base/utils/.ratings b/org.fortiss.tooling.base/trunk/src/org/fortiss/tooling/base/utils/.ratings
index c4e3f226fe303953be952f4f1ca80b740317cd26..a120fef3cc8acee14c383cc910a0b2bbf21ba13b 100644
--- a/org.fortiss.tooling.base/trunk/src/org/fortiss/tooling/base/utils/.ratings
+++ b/org.fortiss.tooling.base/trunk/src/org/fortiss/tooling/base/utils/.ratings
@@ -1,4 +1,3 @@
-
 AngleUtils.java 6aaf8e974481e9bd5c0d813302c1f08d10d1c00d GREEN
 AnnotationUtils.java a70d12c6d96010cda007720bf34b12882940b314 GREEN
 BaseMathUtils.java 7d0e7113af72677b0a7e44fcc40e874624d3bee6 GREEN
@@ -8,7 +7,7 @@ DimensionUtils.java 8508de2b017f5ae76a86cdd0df7ce64a0a5f096e GREEN
 EllipseLayoutUtils.java e5f4f8eac4e4755c84d43a231d346ba348a5d806 GREEN
 LayoutDataUtils.java ee3798cb83903737f146ab1efe22ce667fbbc730 GREEN
 LayoutModelElementFactory.java cf1e7a5b23ae33087e0b8ccf32c37435bc3409fe GREEN
-MigrationUtils.java 06d854e995e308f31c66c9bc933a0bab59e7c803 GREEN
+MigrationUtils.java b63f01ae48cde86d55964b5a26f060fe1db25d56 YELLOW
 OffsetOrientationUtils.java d7afdad0ee75667e04eb4b76e94216dd1ae93070 GREEN
 PointUtils.java 63c055e7c6062c564ceb5d900f3edce15384efc8 GREEN
 PointsUtils.java 5c134ea1a85d290b81634567def23b2f44e0f2ba GREEN
diff --git a/org.fortiss.tooling.base/trunk/src/org/fortiss/tooling/base/utils/MigrationUtils.java b/org.fortiss.tooling.base/trunk/src/org/fortiss/tooling/base/utils/MigrationUtils.java
index 9981a3d970a44e19528b51596298192378e2f6dc..d36b58cc78ac57f03e5468d4cbd37c833475848c 100644
--- a/org.fortiss.tooling.base/trunk/src/org/fortiss/tooling/base/utils/MigrationUtils.java
+++ b/org.fortiss.tooling.base/trunk/src/org/fortiss/tooling/base/utils/MigrationUtils.java
@@ -38,8 +38,9 @@ import org.fortiss.tooling.kernel.model.INamedElement;
  *
  * @author barner
  */
-@Deprecated //ucd
-public class MigrationUtils {
+// TODO To be discussed in the frame of #3243 whether existing migrators should be converted to use
+// these helper methods, or whether to delete this class.
+public class MigrationUtils { // NO_UCD
 
 	/**
 	 * Migrates an {@code oldConnectorBase} (of an (old) concrete sub-type of {@link ConnectorBase})
diff --git a/org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/extension/base/.ratings b/org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/extension/base/.ratings
index 4bd23638aeb494e788271c504dfb6a1d6047b2ce..8d107d4b42bb849dfa899d22a83a131375eedc75 100644
--- a/org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/extension/base/.ratings
+++ b/org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/extension/base/.ratings
@@ -1,11 +1,10 @@
-
 ConstraintBases.java 262582adfab8dc879e7ebb14198b2c98f7194a4d GREEN
 ConstraintCheckerBase.java 8352a59d19fd971b1297052575066f3fae13bfef GREEN
 ConstraintViolationBase.java a5b1fdbdd5ce915789144077ec66b3569142f80c GREEN
 ElementCompositorBase.java 35bf66d2424b412744ae3d700a11c815792a04c0 GREEN
 MultiViolationConstraintCheckerBase.java e2f17f02fae75a17e955d48734ed043323f26f04 GREEN
 PrototypeProviderBase.java 62de3ea391ecb515883490517aa2e94ab812d91b GREEN
-RemoveUnknownFeatureMigrationProviderBase.java 491139a8106bc15f96315e6d65671e8878d6963b GREEN
+RemoveUnknownFeatureMigrationProviderBase.java 57d5260fc8af4c737a14f64a429857dc4fe69f9c YELLOW
 TransformationContextChainBase.java b5195a9bde6d50268dda80fed993477d7a4447ee GREEN
 TransformationProviderBase.java 0c3d114c6a3d854f74630417c05dd889ed02acdf GREEN
 TutorialBlacklistAllProvider.java ce4db7ff751f690a69885cdef5ed84cc1cf61471 GREEN
diff --git a/org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/extension/base/RemoveUnknownFeatureMigrationProviderBase.java b/org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/extension/base/RemoveUnknownFeatureMigrationProviderBase.java
index 5aa87ac1a6aa78d29bfdd6f285a6dfdaed5a7032..c94d7efda650d3df9e556f17564c1930b867da14 100644
--- a/org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/extension/base/RemoveUnknownFeatureMigrationProviderBase.java
+++ b/org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/extension/base/RemoveUnknownFeatureMigrationProviderBase.java
@@ -32,8 +32,10 @@ import org.fortiss.tooling.kernel.extension.data.ITopLevelElement;
  * 
  * @author barner
  */
-@Deprecated //ucd
-public abstract class RemoveUnknownFeatureMigrationProviderBase implements IMigrationProvider {
+// TODO To be discussed in the frame of #3243 whether to keep this as a toolbox to ease
+// implementation of future migrators. See also {@link
+// org.fortiss.tooling.base.utils.MigrationUtils}.
+public abstract class RemoveUnknownFeatureMigrationProviderBase implements IMigrationProvider { // NO_UCD
 
 	/** Type of container previously owning the known unknown feature. */
 	protected Class<?> containerType;