How to mark obsolete classes/methods in the output with sandcastle

Question

I'm building an API documentation with Sandcastle. The code has multiple classes and methods which are marked deprecated. Now I want that in the API-documentation output these methods are clearly marked (crossed-out or other marker). However the Sandcastle output doesn't mark obsolete methods/classes at all.

My question is. What do I need to do to have the obsolete methods/classes marked by Sandcastle.

Thanks for any advice/help.