Thank you for your question.
Unfortunately, there is no build in way to clear the text if it doesn't match the lest. However, you can easily implement it on the LostFocus
event of the RadComboBox.
Please let us know if you have any other questions.
All the best,
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items