title: What is the purpose of the comments in the YAML of a task in the build pipeline visual designer?
body: <p>When I look in the YAML for a task in the visual designer of my build pipeline I see comments like</p>
  
  <pre><code>#Your build pipeline references an undefined variable named ‘Parameters.projects’. Create or edit the build pipeline for this YAML file, define the variable on the Variables tab. See https://go.microsoft.com/fwlink/?linkid=865972
  </code></pre>
  
  <p>Is this an instruction to me to add the Parameters.projects variable or is it just something that is there for me to refer to should I decide to use the YAML in constructing a YAML build pipeline?</p>