<t:choose>
The choose element allows conditional processing of
sub-elements. Template processing continues in the first
<t:when>-subelement where the evaluation
result of the expr-attribute is true.
The evaluation context remains unchanged. If a matching case
is found, no further sub-elements are considered.
If no matching case is found, template processing continues
in the optional {\em<t:otherwise>} element.
Restrictions for Child Elements
Allowed sub-elements are any number of
<t:when> elements, followed by up to one
<t:otherwise> element.