How to create a custom attribute (Beta 2, 3.0 RC0)

You create custom attributes via "System Properties" which is under the admin drop down menu in the upper right corner. To see System Properties the user you're logged on as needs permissions as JazzAdmins or JazzProjectAdmins. Once in System Properties you should see options to configure custom attributes for the various artifacts that support them: Test Plan, Test Case, Test Script, Test Suite, Test Case Result and Test Suite Result.