A user-defined Control element can be explained as a number of simple variable definitions (structure). This structure can be assigned to a configuration group, a computer or a user.

This is how you create a structure:

1. Start the Empirum Management Console (EMC), change in the navigation pane to Management > Administration and select Menu Extras > Variable definitions... or click on the Define variables icon in the toolbar.
2. Click on the Add button.
   You get to the Variable Definition dialog field. Each parameter of the dialog can be found under Adding a Variable Definition.
3. On the right, next to Variable, enter the name for the new variable, e.g. Printer.
4. Via the drop-down field select the variable type Computer.
5. Enter optionally a Description for this variable definition.
6. Via the drop-down field select the User defined Control element.
   
7. Click on the Add button.
   You get back to the Variable Definition dialog field.
8. Configure your structure as you need it by clicking on Add several times.
   Afterwards, the dialog field should look approximately like this:
   
9. If this structure should be able to be assigned any number of times to various objects, activate the Collection option (checkbox ticked).
10. Apply the new variable definition via the OK button.
11. Close the Variable Definitions dialog window via the OK button.

You have created a new structure. You can add values to it via the Variables context menu.