diff --git a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/IPositionConverter.java b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/IPositionConverter.java
index da07eec24b9..8cffe670ba2 100644
--- a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/IPositionConverter.java
+++ b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/IPositionConverter.java
@@ -30,6 +30,13 @@ import org.eclipse.jface.text.Position;
  * the deletion as far as possible.
  * 
  * <p> This interface is not intended to be implemented by clients. </p>
+ * 
+ * <p>
+ * <strong>EXPERIMENTAL</strong>. This interface has been added as
+ * part of a work in progress. There is no guarantee that this API will
+ * work or that it will remain the same. Please do not use this API without
+ * consulting with the CDT team.
+ * </p>
  */
 
 public interface IPositionConverter {
diff --git a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/IPositionTrackerManager.java b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/IPositionTrackerManager.java
index 80a9da311b8..684e8ee5292 100644
--- a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/IPositionTrackerManager.java
+++ b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/IPositionTrackerManager.java
@@ -20,6 +20,13 @@ import org.eclipse.core.runtime.IPath;
  * for the file.
  * 
  * <p> This interface is not intended to be implemented by clients. </p>
+ * 
+ * <p>
+ * <strong>EXPERIMENTAL</strong>. This interface has been added as
+ * part of a work in progress. There is no guarantee that this API will
+ * work or that it will remain the same. Please do not use this API without
+ * consulting with the CDT team.
+ * </p>
  */
 public interface IPositionTrackerManager {
     /**