title: What does this symbol mean in IntelliJ? (red circle on bottom-left corner of file name, with 'J' in it)
body: <p>Under the target folder in IntelliJ for a Java project I created, I have a few java source files in the package.  Beside each file the 'J' icon has a red circle with a line through it.</p>
  
  <p>What does that mean?  How do I fix it?</p>