title: VS2019 custom template - parent variable prefix (ext_) not working
body: <p>I am trying to create a custom template for VS2019 comprised of multiple projects (based on <a href="https://blog.jayway.com/2015/03/13/visual-studio-how-to-create-a-solution-template-with-multiple-projects/" rel="nofollow noreferrer">this</a> guide), and I'm having problems with the references.</p>
  
  <p>My solution is based on the classic 3-tier architecture (data/business/ui), so when I create a new solution - call it "MySolution", I get "MySolution.Data", "MySolution.Business" and "MySolution.UI" - all good. I need the business layer to have a reference to the data layer - however, using the <code>$ext_safeprojectname$</code> variable just gives me an unresolved reference in the projects node of my dependencies to "$ext_safeprojectname$.Data"</p>
  
  <p>Other variables seem to work fine - for example, if I use <code>$safeprojectname$</code>, I get "MySolution.Business.Data" in my reference - correct parsing of the variable, for the business layer project, but not the desired result.</p>
  
  <p>Has the <code>ext_</code> prefix been replaced? I cannot seem to find any documentation for this anywhere.</p>
  
  <p>Thanks!</p>