diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index e6923c3..44063c3 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -82,8 +82,10 @@
      <member><literal>NOT</></member>
     </simplelist>
 
-    <acronym>SQL</acronym> uses a three-valued Boolean logic where the null value represents
-    <quote>unknown</quote>.  Observe the following truth tables:
+    <para>
+     <acronym>SQL</acronym> uses a three-valued Boolean logic where the null value represents
+     <quote>unknown</quote>.  Observe the following truth tables:
+    </para>
 
     <informaltable>
      <tgroup cols="4">