diff --git a/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java b/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
index ecd8e3f..fc6b024 100644
--- a/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
+++ b/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
@@ -57,7 +57,7 @@
  * <p>
  * As of 3.2, AbstractTreeViewer supports multiple equal elements (each with a
  * different parent chain) in the tree. This support requires that clients
- * enable the element map by calling <code>setUseHashLookup(true)</code>.
+ * enable the element map by calling <code>setUseHashlookup(true)</code>.
  * </p>
  * <p>
  * Content providers for abstract tree viewers must implement one of the
diff --git a/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java b/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
index 960c370..267cefa 100644
--- a/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
+++ b/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
@@ -1745,10 +1745,15 @@
 	 * Configures whether this structured viewer uses an internal hash table to
 	 * speed up the mapping between elements and SWT items. This must be called
 	 * before the viewer is given an input (via <code>setInput</code>).
-	 *
-	 * @param enable
-	 *            <code>true</code> to enable hash lookup, and
-	 *            <code>false</code> to disable it
+	 * <p>
+	 * Note: enabling hash lookup requires from client code that elements managed by
+	 * the viewer properly implement {@link #hashCode()} and {@link #equals(Object)}
+	 * and that equal elements are not added to the same parent in the tree (each
+	 * equal element should have a different parent chain).
+	 * </p>
+	 * 
+	 * @param enable <code>true</code> to enable hash lookup, and <code>false</code>
+	 *               to disable it
 	 */
 	public void setUseHashlookup(boolean enable) {
 		Assert.isTrue(getInput() == null,
diff --git a/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java b/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
index 8172e95..b3de0b0 100644
--- a/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
+++ b/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
@@ -47,7 +47,7 @@
  * <p>
  * As of 3.2, TreeViewer supports multiple equal elements (each with a
  * different parent chain) in the tree. This support requires that clients
- * enable the element map by calling <code>setUseHashLookup(true)</code>.
+ * enable the element map by calling <code>setUseHashlookup(true)</code>.
  * </p>
  * <p>
  * Content providers for tree viewers must implement either the