 is 
 found the resulting param value will then be parsed as a subquery, and 
 returned as the parse result.
 </p>
 <p>
 The "<code>case</code>" local param can be optionally be specified as a 
 switch case to match missing (or blank) input strings.  
 The "<code>default</code>" local param can optionally be specified 
 as a default case to use if the input string does not match any other 
 switch case local params.  If <code>default</code> is not specified, 
 then any input which does not match a switch ca