diff --git a/appendices/comparisons.xml b/appendices/comparisons.xml
index 1162813a8b..4be5aa0193 100644
--- a/appendices/comparisons.xml
+++ b/appendices/comparisons.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.4 $ -->
+<!-- $Revision: 1.5 $ -->
 <appendix id="types.comparisons">
  <title>PHP type comparison tables</title>
  <para>
@@ -40,7 +40,7 @@
    <tgroup cols="6">
     <thead>
      <row>
-      <entry>&nbsp;</entry>
+      <entry>Expression</entry>
       <entry><function>gettype</function></entry>
       <entry><function>empty</function></entry>
       <entry><function>is_null</function></entry>
@@ -196,7 +196,7 @@
    <tgroup cols="12">
     <thead>
      <row>
-      <entry>&nbsp;</entry>
+      <entry> </entry>
       <entry>&true;</entry>
       <entry>&false;</entry>
       <entry><literal>1</literal></entry>
@@ -376,7 +376,7 @@
    <tgroup cols="12">
     <thead>
      <row>
-      <entry>&nbsp;</entry>
+      <entry> </entry>
       <entry>&true;</entry>
       <entry>&false;</entry>
       <entry><literal>1</literal></entry>