ICU rules may be specified as CDATA below the rule

This allows for multi-line rules, such as ICU custom transliterators.
For example:
<icu_chain locale="en">
 <transliterate>
$back = \` ;
$back $back > “ ; # generate right d.q.m. (double quotation mark)
$back > ‘ ;
</transliterate>
</icu_chain>