Improve constraint_name wording.

doc/src/sgml/ref/create_table.sgml

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-$PostgreSQL: pgsql/doc/src/sgml/ref/create_table.sgml,v 1.98 2006/01/16 19:53:12 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/create_table.sgml,v 1.99 2006/01/16 20:48:49 momjian Exp $
 PostgreSQL documentation
 -->
 
@@ -295,10 +295,10 @@ and <replaceable class="PARAMETER">table_constraint</replaceable> is:
      <para>
       An optional name for a column or table constraint.  If the
       constraint is violated, the constraint name is present in error messages,
-      so constraint names like <literal>"col must be positive"</> can be used
+      so constraint names like <literal>col must be positive</> can be used
       to communicate helpful constraint information to client applications.
-      (Double-quotes are required for constraint names that contain spaces.)
-      If not specified, the system generates a name.
+      (Double-quotes are needed to specify constraint names that contain spaces.)
+      If a constraint name is not specified, the system generates a name.
      </para>
     </listitem>
    </varlistentry>