diff --git a/concurrent/CountingStream.java b/concurrent/CountingStream.java
index ca55bffe..8ab2ba11 100644
--- a/concurrent/CountingStream.java
+++ b/concurrent/CountingStream.java
@@ -2,6 +2,7 @@
 // (c)2017 MindView LLC: see Copyright.txt
 // We make no guarantees that this code is fit for any purpose.
 // Visit http://OnJava8.com for more book information.
+// {ValidateByHand}
 import java.util.*;
 import java.util.concurrent.*;
 import java.util.stream.*;
diff --git a/newio/AvailableCharSets.java b/newio/AvailableCharSets.java
index 66b1b77c..b46b3dfb 100644
--- a/newio/AvailableCharSets.java
+++ b/newio/AvailableCharSets.java
@@ -3,7 +3,6 @@
 // We make no guarantees that this code is fit for any purpose.
 // Visit http://OnJava8.com for more book information.
 // Displays Charsets and aliases
-// !!!! CI has trouble
 import java.nio.charset.*;
 import java.util.*;
 
diff --git a/onjava/HTMLColors.java b/onjava/HTMLColors.java
index f960d23a..e84b9c90 100644
--- a/onjava/HTMLColors.java
+++ b/onjava/HTMLColors.java
@@ -224,7 +224,7 @@ public class HTMLColors {
       .limit(count)
       .forEach(e ->
         System.out.format(
-          "%-20s  0x%06X\n", e.getKey(), e.getValue()));
+          "%-20s  0x%06X%n", e.getKey(), e.getValue()));
   }
   public static void showInv(Map<String,Integer> m) {
     showInv(m, m.size());
diff --git a/operators/Underscores.java b/operators/Underscores.java
index 2805f43e..cd862fb8 100644
--- a/operators/Underscores.java
+++ b/operators/Underscores.java
@@ -9,7 +9,7 @@ public class Underscores {
     System.out.println(d);
     int bin = 0b0010_1111_1010_1111_1010_1111_1010_1111;
     System.out.println(Integer.toBinaryString(bin));
-    System.out.printf("%x%n", bin);
+    System.out.printf("%x%n", bin);  // [1]
     long hex = 0x7f_e9_b7_aa;
     System.out.printf("%x%n", hex);
   }