Uppercase CHECK mention in relchecks documentation mention.

doc/src/sgml/catalogs.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.195 2009/02/07 15:00:27 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.196 2009/02/07 19:27:25 momjian Exp $ -->
 <!--
  Documentation of the system catalogs, directed toward PostgreSQL developers
  -->
@@ -1738,7 +1738,7 @@
       <entry><type>int2</type></entry>
       <entry></entry>
       <entry>
-       Number of check constraints on the table; see
+       Number of <literal>CHECK</> constraints on the table; see
        <link linkend="catalog-pg-constraint"><structname>pg_constraint</structname></link> catalog
       </entry>
      </row>