making search terms not selectable

[do...@doppy.nl]

I'm using select2 with an ajax request to search for possible choices in a huge database. This works fine.

However, it is possible for the user to select the "searchterm" they entered. This is then added with value+display as an option to the select+option and passed to the server when the form is submitted.

Is there a way to prevent the user from selecting his own search term?
Or is there a way to "clear" the input and just make the select "nothing selected" when this happens?

Thank you
DoppyNL