</para>
 
   <sect2 id="prepare-publisher-upgrades">
-   <title>Prepare for publisher upgrades</title>
+   <title>Prepare for Publisher Upgrades</title>
 
    <para>
     <application>pg_upgrade</application> attempts to migrate logical
   </sect2>
 
   <sect2 id="prepare-subscriber-upgrades">
-   <title>Prepare for subscriber upgrades</title>
+   <title>Prepare for Subscriber Upgrades</title>
 
    <para>
     Setup the <link linkend="logical-replication-config-subscriber">
   </sect2>
 
   <sect2 id="upgrading-logical-replication-clusters">
-   <title>Upgrading logical replication clusters</title>
+   <title>Upgrading Logical Replication Clusters</title>
 
    <para>
     While upgrading a subscriber, write operations can be performed in the
    </para>
 
    <sect3 id="steps-two-node-logical-replication-cluster">
-    <title>Steps to upgrade a two-node logical replication cluster</title>
+    <title>Steps to Upgrade a Two-node Logical Replication Cluster</title>
      <para>
       Let's say publisher is in <literal>node1</literal> and subscriber is
       in <literal>node2</literal>. The subscriber <literal>node2</literal> has
     </sect3>
 
     <sect3 id="steps-cascaded-logical-replication-cluster">
-     <title>Steps to upgrade a cascaded logical replication cluster</title>
+     <title>Steps to Upgrade a Cascaded Logical Replication Cluster</title>
      <para>
       Let's say we have a cascaded logical replication setup
       <literal>node1</literal>-><literal>node2</literal>-><literal>node3</literal>.
     </sect3>
 
     <sect3 id="steps-two-node-circular-logical-replication-cluster">
-     <title>Steps to upgrade a two-node circular logical replication cluster</title>
+     <title>Steps to Upgrade a Two-node Circular Logical Replication Cluster</title>
      <para>
       Let's say we have a circular logical replication setup
       <literal>node1</literal>-><literal>node2</literal> and
 
   </sect2>
 
   <sect2 id="protocol-versions">
-   <title>Protocol versions</title>
+   <title>Protocol Versions</title>
 
    <para>
     The current, latest version of the protocol is version 3.2. However, for
    </para>
 
    <table id="protocol-versions-table">
-    <title>Protocol versions</title>
+    <title>Protocol Versions</title>
 
     <tgroup cols="3">
      <thead>