How to exclude a content type ?

Hi.

I have a facet that shows nodes that are endpoints in some relations build by the relation module. These nodes are of two different content types : "course" and "ressource".

In the Facetapi_bonus description it is said that it is possble to exclude node of a specific content type :

Filter "Exclude Items": Filter plugin to exclude certain facet items by their markup/title or internal value (say excluding "page" from "content types"). Regexp are also possible.

Can you please specify the syntax to add in the "Exlude items" field to reach this goal, because after several trials i did not yet succeed to exclude all node of content type "ressource" from the facet.

Thanks a lot !

Gregoire