Help:Parser functions in templates

When using ParserFunctions in Template parameters, a pipe symbol ("|") may be used to indicate which way to handle things if a parameter is or is not passed in.


 *  


 * Sample:  


 * Result: 


 *  


 * Sample:  


 * Result: 

The second usage is more common, and correctly handles situations where a parameter exists, but is comprised only of empty space.