diff --git a/docs/snippets/Snippets.NUnit/Constraints/ConstraintExamples.cs b/docs/snippets/Snippets.NUnit/Constraints/ConstraintExamples.cs
index e1588ade4..7824664ee 100644
--- a/docs/snippets/Snippets.NUnit/Constraints/ConstraintExamples.cs
+++ b/docs/snippets/Snippets.NUnit/Constraints/ConstraintExamples.cs
@@ -60,6 +60,9 @@ public void AnyOfCanDetectIfAnItemMatchesAnArrayOfParams()
         public void AnyOfCanUseCustomComparisons()
         {
             var testValue = "NUnit";
+
+            // NOTE: Here we cast our comparison to IComparer, because StringComparer implements
+            // multiple interfaces that NUnit custom comparisons supports.
             Assert.That(testValue, Is.AnyOf("hello", "world", "nunit").Using((IComparer)StringComparer.InvariantCultureIgnoreCase));
         }
         #endregion