Under Custom Data Types, input or output parameters of a web service can be created in the form of an input list or structure.
The following settings are available:
Add a new custom data type
Creation of a new custom data type.
Edit
Edit existing custom data types.
Copy
Copy a custom data type.
Remove selected custom data type
Remove the selected custom data type.
Remove all unused custom data types
Remove all unused custom data types. A custom data type is not used if it is not used as an input or output parameter in the designer.
Move custom data type up/ down
Change the sort order of the listed custom data types.
Sort custom data types alphabetically
Alphabetically sort the custom data types.
For detailed information on how to create and use Custom Data Types take a look here.