In most applications you need to parameterise your content structures. If for instance your content structure consists of one or several database queries, you might want the queries to take a parameter as input. Another example is if you have developed a script that retrieves articles published between two dates, you would want to send start and end date as parameters.

There are four mechanisms you can you use to parameterise your content structures:

• Parameters
• Lookup tables
• Built-in variables
• Global constants