Clarify confold and confnew handling

man/en/dpkg.8.sgml

@@ -1048,7 +1048,9 @@
 
 	      <listitem><para>
 		If a conffile has been modified always install the new
-		version without prompting.
+		version without prompting, unless the
+		<option>--force-confdef</option> is also specified, in
+		which case the default action is preferred.
 	      </para></listitem>
 	    </varlistentry>
 
@@ -1057,7 +1059,9 @@
 
 	      <listitem><para>
 		If a conffile has been modified always keep the old version
-		without prompting.
+		without prompting, unless the <option>--force-confdef</option>
+		is also specified, in which case the default action is
+		preferred.
 	      </para></listitem>
 	    </varlistentry>