diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/Renderers.java b/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/Renderers.java
index c4ad257f721..39e8ec68997 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/Renderers.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/Renderers.java
@@ -421,7 +421,7 @@ public class Renderers {
                            " that cannot be satisfied capturing 'in' projection";
         }
         else {
-            explanation = "Only top level type projections can be captured";
+            explanation = "Only top-level type projections can be captured";
         }
         result.text(newText().normal("'" + typeParameterWithCapturedConstraint.getName() + "'" +
                                      " cannot capture " +
diff --git a/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystemStatus.kt b/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystemStatus.kt
index 793fdf67415..bc7dcd0b141 100644
--- a/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystemStatus.kt
+++ b/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystemStatus.kt
@@ -86,6 +86,11 @@ public trait ConstraintSystemStatus {
      */
     public fun hasErrorInConstrainingTypes(): Boolean
 
-    //todo comment
+    /**
+     * Returns <tt>true</tt> if a user type contains the type projection that cannot be captured.
+     *
+     * For example, for <pre>fun &lt;T&gt; foo(t: Array&lt;Array&lt;T&gt;&gt;) {}</pre>
+     * in invocation <tt>foo(array)</tt> where array has type <tt>Array&lt;Array&lt;out Int&gt;&gt;</tt>.
+     */
     public fun hasCannotCaptureTypesError(): Boolean
 }
\ No newline at end of file