diff --git a/doc/arm/Bv9ARM-book.xml b/doc/arm/Bv9ARM-book.xml
index b7e268bd09..01a7041a10 100644
--- a/doc/arm/Bv9ARM-book.xml
+++ b/doc/arm/Bv9ARM-book.xml
@@ -6154,12 +6154,15 @@ options {
 	    <varlistentry>
 	      <term><command>message-compression</command></term> <listitem>
 		<para>
-		  If <userinput>yes</userinput>, DNS name compression will
-		  be used for responses to regular queries (not including
+		  If <userinput>yes</userinput>, DNS name compression is
+		  used in responses to regular queries (not including
 		  AXFR or IXFR, which always uses compression).  Setting
-		  this option to <userinput>no</userinput> can result in
-		  larger responses, but will reduce CPU usage on servers.
-		  The default is <userinput>yes</userinput>.
+		  this option to <userinput>no</userinput> reduces CPU
+		  usage on servers and may improve throughput.  However,
+		  it increases response size, which may cause more queries
+		  to be processed using TCP; a server with compression
+		  disabled is out of compiance with RFC 1123 Section
+		  6.1.3.2. The default is <userinput>yes</userinput>.
 		</para>
 	      </listitem>
 	    </varlistentry>
@@ -6699,7 +6702,7 @@ options {
 	    <varlistentry>
 	      <term><command>auto-dnssec</command></term>
 	      <listitem>
-	        <para>
+		<para>
 		  Zones configured for dynamic DNS may use this
 		  option to allow varying levels of automatic DNSSEC key
 		  management. There are three possible settings: