Thank you for your question.
These tasks can be easily hidden with our powerful filtering capabilities (See more >> http://usermanual.clarizen.com/#10-5-3-seraching-and-filtering). For further clarification, please hop on Q&A webinar and ask for a demo. We will be happy to walk you through this. Here is the link to register >> http://clarizenusa.adobeconnect.com/qa .
All the best,