Hi Stefan,

If I understand correctly, you are talking about the RadMultiColumnComboBox's border separator of the SearchAutoCompleteBox and the DropDownButton, which is used to indicate that these parts have different logical scopes and that the first one is the editor part that will contain the items and the second part opens the list from which you choose these items.

The RadComboBox control, compared to the RadMultiColumnComboBox, has two modes - non-editable and editable, which have that exact difference - the border separator. Therefore, the design for the non-editable RadComboBox is different from the one for the editable RadComboBox.

Please refer to the screenshot attached that compares the two controls - RadComboBox with its two modes and the RadMultiColumnComboBox which has only editable mode.

Regards,
Vicky
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