Stylesheet Parameters
The Stylesheet Parameters command 
enables you to declare and edit parameters and their default values. The command is available in both the Design Document view and the Authentic Editor View. When you click this command, the Edit Parameters dialog (shown below) pops up.
The following points should be noted:
•You can insert, append, edit and delete parameters for the entire stylesheet and for the DB Filters.
•Parameter names must begin with a letter, and can contain the characters A to Z, a to z, 0 to 9, and the underscore.
•The Edit Parameters dialog contains all the user-defined parameters in an SPS.
•Parameters can also be declared in the Design Overview sidebar.