Document comparison ignoring diacritics and case sensitivity

reference/intl/collator/compare.xml

@@ -127,6 +127,33 @@ if ($res === false) {
     </screen>
    </example>
   </para>
+  <para>
+   <example>
+    <title>Comparing strings without diacritics or case-sensitivy</title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+$c = new Collator( 'en' );
+$c->setStrength( Collator::PRIMARY );
+
+if ( $c->compare( 'Séan', 'Sean' ) == 0 )
+{
+    echo "The same\n";
+}
+]]>
+    </programlisting>
+    &example.outputs;
+    <screen>
+     The same
+    </screen>
+    <para>
+     This example instructs the collator to compare with only taking the base
+     characters into account. The documentation for
+     <function>Collator->setStrength</function> explains the different
+     strengths.
+    </para>
+   </example>
+  </para>
  </refsect1>
 
  <refsect1 role="seealso">