title: SharePoint 2010: Is it possible to declare list relations without having list instances?
body: <p>First of all I have to excuse for the maybe misleading question: I read that it's not possible, so the question actually is: Is this true and if yes, is there another possibility to accomplish this relation-behavior? But let's describe my situation:</p>
  
  <p>I'm developing a small SharePoint 2010 solution and am not sure how to deploy some relations. I want to deploy everything with only the help of packages and features, that means I cannot use the SharePoint UI.  That's what I want to do:</p>
  
  <p>I'm designing several content types, e.g. <em>Report</em> and <em>Entry</em>. I'm using XML-Definitions to design them. Then I build list definitions that describe that e.g. the <em>ReportList</em> handles items of the type <em>Report</em>. And now I'm stuck: I want to declare that every <em>Entry</em> belongs to one <em>Report</em>. Therefore I'm adding a lookup field to the definition of the content type for <em>Entry</em>, but lookup fields need list instances when I deploy their content types.</p>
  
  <p>I would like to declare the relation without a need of these instances. Users should have the ability to decide which lists they want to add for themselves. Is there a best practice for declaring such relation without having list instances?</p>