I created a project in DOORS NG, added a module and some Business and System requirements.  The project was created with the Traditional template.  I was able to create Validated By links to test cases I created in a QM project.  I created another DOORS NG project with the Traditional template and a new QM project of the same name.  After creating some modules and requirements in the new project and a few test cases in the new QM project, I tried to create Validated By links from some Business Requirements and System Requirements to related test cases, by the Validated By link was not available.  It is listed in the Link Types under Project properties, but when I go to Artifact Types and select one of the types I am using, it is not available to add in the Preferred Link Types to add list.  How do I add Validated By to the requirement Artifact Types that I need?