A variable can be a String, String list, String table, document, document list, document reference, document reference list, Object, or Object list. Variables are used to declare the expected content and structure of service signatures, document contents, and pipeline contents. In addition to specifying the name and data type of a variable, you can set properties that specify an XML namespace, indicate whether the variable is required at runtime, and indicate whether the variable can be null at runtime.

Select a variable in the editor to set general properties and constraints for the variable. Specific properties in the Properties view are enabled or disabled, depending on the type of variable you have selected.