@@ -243,11 +243,17 @@ CREATE COLLATION german_phonebook (provider = icu, locale = 'de-u-co-phonebk');
243243 </para>
244244
245245 <para>
246- To create a collation using the ICU provider, based on theEnglish ICU
247- locale, with custom rules:
246+ To create a collation using the ICU provider, based on theroot ICU locale,
247+ with custom rules:
248248<programlisting>
249- <![CDATA[CREATE COLLATIONen_custom (provider = icu, locale = 'en ', rules = '&a < g ');]]>
249+ <![CDATA[CREATE COLLATIONcustom (provider = icu, locale = 'und ', rules = '&V << w <<< W ');]]>
250250</programlisting>
251+ With this rule, the letter <quote>W</quote> is sorted after
252+ <quote>V</quote>, but is treated as a secondary difference similar to an
253+ accent. Rules like this are contained in the locale definitions of some
254+ languages. (Of course, if a locale definition already contains the desired
255+ rules, then they don't need to be specified again explicitly.) See the ICU
256+ documentation for further details and examples on the rules syntax.
251257 </para>
252258
253259 <para>